A Design Vocabulary

Figure depicting the diagram of the human eye, where optic nerve, peripheral vision, color vision, and fine focus are labeled.

Our ability to focus on and perceive detail is restricted to a fairly narrow cone of vision. In surveying our visual field, our eyes continually move, scan, focus, and refocus to discover visual information. To make sense of what we see, the brain interprets the visual data gathered by our eyes and assembles the information into visual patterns that we can recognize and understand.

The normal process of perception is utilitarian and geared toward recognition. When we see a chair, we recognize it to be a chair if its form and configuration fit a pattern established by chairs we have seen and used in the past. If we look carefully, however, we will also be able to perceive the chair's specific shape, size, proportion, color, texture, and material. This ability to see beyond recognition and utility is extremely important to designers. We must continually strive to see and be conscious of the specific visual characteristics of things and how they relate to and interact with each other to form the aesthetic quality of our visual environments.

Traditionally, two types of photoreceptors in the mammalian retina were accepted by scientists: rods (which saw in black and white) and cones (which perceived in color). In 2002, the Brown University scientist David Berson identified an entirely new class of photoreceptor, the ipRGC, which is sensitive to short-wavelength (blue) light. The ipRGC is the main conduit of light signals from the retina to the brain, and receives processed input from rods and cones. Its discovery radically changed how lighting is measured, manufactured, specified, and applied. It has led to a proposal for a model of human circadian phototransduction—the means by which the retina converts light signals into neural signals for the circadian system—to quantify circadian-effective light. A new way of quantifying light's impact on the circadian system called circadian stimulus (CS) allows predictions of how spectral power distributions and light levels will suppress the hormone melatonin at night. CS has impacts on sleep quality and quantity, performance, fatigue, mood, and behavior in people including older adults with Alzheimer's disease, office workers, and cancer patients; this obviously affects the design of interior spaces. (Architectural Lighting, Nov./Dec. 2016).

Our perception of the visual shape, size, color, and texture of things is affected by the optical environment in which we see them and the relationships we can discern between them and their visual setting. If our visual field were undifferentiated, we would be unable to identify anything. As a perceptible change in tonal value, color, and texture occurred, however, we would begin to discern an object or figure as differentiated from its background. To read the lines, shapes, and forms of objects in our field of vision, therefore, we must first perceive contrast between them and their background.

Figure (top) depicting sketches of two chairs and a sofa drawn inside a circle. A sketch (bottom) depicting figure–ground relationships.

Those elements that appear to stand out from or in front of their background are called figures. In addition to tonal value contrast, what distinguishes a figure from its background is its shape and size relative to its field. While a figure shares a common border with its background, it has a more distinct and recognizable shape that makes it appear as an object. Figures are sometimes referred to as positive elements—having a positive shape—while backgrounds are described as negative or neutral elements—lacking a clear or discernible shape.

Figures are most discernible when surrounded by a generous amount of space or background. When the size of a figure is such that it crowds its background, the background can develop its own distinct shape and interact with the shape of the figure. At times, an ambiguous figure–ground relationship can occur wherein elements in a composition can be seen alternately, but not simultaneously, as both figure and ground.

Our visual world is, in reality, a composite image constructed from a continuous array of figure–ground relationships. In interior design, these relationships can be seen to exist at several scales, depending on one's point of view.

Form refers to the shape and structure of something, as distinguished from its substance or material. The point is the generator of all form. As a point moves, it leaves a trace of a line—the first dimension. As the line shifts in direction, it defines a plane—a two-dimensional element. The plane, extended in a direction oblique or perpendicular to its surface, forms a three-dimensional volume.

Point, line, plane, and volume—these are the primary elements of form. All visible forms are, in reality, three-dimensional. In describing form, these primary elements differ according to their relative dimensions of length, width, and depth—a matter of proportion and scale.

Many existing buildings have forms that are organized for particular uses, often with low ceilings, many walls, and windows that precisely correspond to interior arrangements, making them difficult to adapt and reuse. Other buildings are built as sustainable shells, with generous floor-to-ceiling heights, open floor plans, long structural spans with high load-bearing capacities, and large mechanical and circulation areas. These buildings combine a durable, flexible building type with a development model that will function in both the short and long term.

Figure depicting the examples of point, line, plane, and volume.

A point marks a location in space. Conceptually, it has no length, width, or depth. It is, therefore, static and directionless. As the prime generator of form, a point can mark the end of a line, the intersection of two lines, or the corner where the lines of a plane or volume meet.

As a visible form, a point is most commonly manifested as a dot, a circular shape that is small relative to its field. Other shapes can also be seen as point forms if sufficiently small, compact, and nondirectional.

When at the center of a field or space, a point is stable and at rest, and capable of organizing other elements about itself. When moved off-center, it retains its self-centering quality but becomes more dynamic. Visual tension is created between the point and its field. Point-generated forms, such as the circle and the sphere, share this self-centering quality of the point.

Figure depicting point-generated forms: centered, off-centered, reinforcing a point, and center of attention. — Point-generated forms, such as the circle and the sphere, are self-centering.

A point extended becomes a line. Conceptually, a line has only one dimension, length. In reality, a line's length visually dominates whatever thickness it must have to be visible. Unlike a point, which is static and directionless, a line is capable of expressing movement, direction, and growth.

As visible forms, lines may vary in weight and character. Whether bold or delicate, taut or limp, graceful or jagged, a line's visual character is due to our perception of its length-to-width ratio, its contour, and its degree of continuity.

A line can also be implied by two points. Carried further, the simple repetition of similar elements, if continuous enough, can define a line with significant textural qualities.

Figure depicting the lines that vary in weight, contour, and texture. — Lines can vary in weight, contour, and texture.

A straight line represents the tension that exists between two points. An important characteristic of a straight line is its direction. A horizontal line can represent stability, repose, or the plane upon which we stand or move. In contrast to this, a vertical line can express a state of equilibrium with the force of gravity.

Diagonal lines, deviations from the horizontal and the vertical, can be seen as rising or falling. In either case, they imply movement and are visually active and dynamic.

A curved line represents movement deflected by lateral forces. Curved lines tend to express gentle movement. Depending on their orientation, they can be uplifting or represent solidity and attachment to the earth. Small curves can express playfulness, energy, or patterns of biological growth.

Line is an essential element in the formation of any visual construction. Without lines, we would not be able to define shape—that characteristic by which we generally recognize things. Lines describe the edges of shape and separate it from the space around it. In addition, the contours of these lines imbue the shape with their expressive qualities.

In addition to describing shape, lines can articulate the edges of planes and the corners of volumes. These lines can be expressed either by the absence of material—reveals and recessed joints—or by the application of trim.

Lines can also be used to create texture and patterns on the surfaces of forms.

Figure (top) depicting lines defining shapes that include a square, a circle, and a triangle. Figure (middle) depicting a desk and three chairs. Figure (bottom) depicting a table and a rest a relaxing chair.

Figure depicting lines articulating edges and lines creating textures and patterns.

Linear forms have traditionally been used to provide vertical support, to span and express movement across space, and to define the edges of spatial volumes. This structural role of linear elements can be seen at the scale of architecture and interior space, and in furnishings.

Within the design process itself, lines are used as regulating devices to express relationships and establish patterns among design elements.

Figure depicting the shapes made by lines. — We often use lines to regulate relationships in drawing and design.

A line shifted in a direction other than its intrinsic direction defines a plane. Conceptually, a plane has two dimensions—width and length—but no depth. In reality, a plane's width and length dominate whatever thickness it must have to be visible.

Shape is the primary characteristic of a plane. It is described by the contour of the lines defining the edges of the plane. Since our perceptions of a plane's shape can be distorted by perspective, we see the true shape of a plane only when we view it frontally.

In addition to shape, planar forms have significant surface qualities of material, color, texture, and pattern. These visual characteristics affect the qualities of a plane:

Visual weight and stability
Perceived size, proportion, and position in space
Light reflectivity
Tactile characteristics
Acoustic properties

The shapes (top) depicting the example of material and color. The shapes (bottom) depicting the example of texture and pattern. — Planar elements have surface characteristics of material, color, texture, and pattern.

Planar forms are fundamental elements of architecture and interior design. Floor, wall, and ceiling or roof planes serve to enclose and define three-dimensional volumes of space. Their specific visual characteristics and their relationships in space determine the form and character of the space they define. Within these spaces, furnishings and other interior design elements can also be seen to consist of planar forms.

The interior designs depicting the examples of planar forms.

Shape is the primary means by which we distinguish one form from another. It may refer to the contour of a line, the outline of a plane, or the boundary of a three-dimensional mass. In each case, shape is defined by the specific configuration of the lines or planes that separates a form from its background or surrounding space.

There are several broad categories of shapes. Natural shapes represent the images and forms of our natural world. These shapes may be abstracted, usually through a process of simplification, and still retain the essential characteristics of their natural sources.

Nonobjective shapes make no obvious reference to a specific object or to a particular subject matter. Some nonobjective shapes may result from a process, such as calligraphy, and carry meaning as symbols. Others may be geometric and elicit responses based on their purely visual qualities.

Geometric shapes dominate the built environment of both architecture and interior deign. There are two separate and distinct types of geometric shapes—rectilinear and curvilinear. In their most regular form, curvilinear shapes are circular, while rectilinear shapes include the series of polygons that can be inscribed within a circle. Of these, the most significant geometric shapes are the circle, the triangle, and the square. Extended into the third dimension, these primary shapes generate the sphere, the cylinder, the cone, the pyramid, and the cube.

Figure depicting the examples of natural, nonobjective, and geometric shapes.

Figure depicting the different geometrical shapes: sphere, cylinder, cone, pyramid, and cube.

The circle is a compact, introverted shape that has its center point as its natural focus. It represents unity, continuity, and economy of form.

A circular shape is normally stable and self-centering in its environment. When associated with other lines and shapes, however, a circle can appear to have motion.

Other curvilinear lines and shapes can be seen to be fragments or combinations of circular shapes. Whether regular or irregular, curvilinear shapes are capable of expressing softness of form, fluidity of movement, or the nature of biological growth.

The triangle represents stability. Triangular shapes and patterns are often used in structural systems, since their configuration cannot be altered without bending or breaking one of their sides.

From a purely visual point of view, a triangular shape is perceived as stable when resting on one of its sides. When tipped to stand on one of its points, however, the triangular shape becomes dynamic. It can exist in a precarious state of balance or imply motion, as it tends to fall over onto one of its sides.

The dynamic quality of a triangular shape is also due to the angular relationships of its three sides. Because these angles can vary, triangles are more flexible than squares and rectangles. In addition, triangles can be conveniently combined to form any number of square, rectangular, and other polygonal shapes.

Figure depicting triangular shapes and patterns.

Figure depicting the shapes made by joining multiple triangles.

Figure depicting the shape of Seconda chair.

The square represents the pure and the rational. The equality of its four sides and its four right angles contributes to its regularity and visual clarity.

A square shape has no preferred or dominant direction. Like the triangle, the square is a stable, tranquil figure when resting on one of its sides, but becomes dynamic when standing on one of its corners.

All other rectangles can be considered to be variations of the square with the addition of width or length. While the clarity and stability of rectangular shapes can lead to visual monotony, variety can be introduced by varying their size, proportion, color, texture, placement, or orientation.

Texture is the specific quality of a surface that results from its three-dimensional structure. Texture is most often used to describe the relative smoothness or roughness of a surface. It can also be used to describe the characteristic surface qualities of familiar materials, such as the roughness of stone, the grain of wood, and the weave of a fabric.

There are two basic types of texture. Tactile texture is real and can be felt by touch; visual texture is seen by the eye. All tactile textures provide visual texture as well. Visual texture, on the other hand, may be illusory or real.

Our senses of sight and touch are closely intertwined. As our eyes read the visual texture of a surface, we often respond to its apparent tactile quality without actually touching it. We base these physical reactions to the textural qualities of surfaces on previous associations with similar materials.

Digitally dazed individuals are looking for real textures they can touch. Shoppers form stronger impressions about products with which they can physically interact.Touch is very closely related to emotional feelings.

Figure depicting the texture that defines the three-dimensional structure of a surface. — Texture refers to the three-dimensional structure of a surface.

Figure depicting physical and visual textures.

Figure (top) depicting some examples of textures and the surfaces. Figure (bottom) depicting some examples of far and near textures.

Scale, viewing distance, and light are important modifying factors in our perception of textures and the surfaces they articulate.

All materials have some degree of texture, but the finer the scale of a textural pattern is, the smoother it will appear to be. Even coarse textures, when seen from a distance, can appear to be relatively smooth. Only upon closer viewing will the texture's coarseness become evident.

The relative scale of a texture can affect the apparent shape and position of a plane in space. Textures with a directional grain can accentuate a plane's length or width. Coarse textures can make a plane appear closer, reduce its scale, and increase its visual weight. In general, textures tend to fill the space in which they exist visually.

Light influences our perception of texture and, in turn, is affected by the texture it illuminates. Direct light falling across a surface with physical texture will enhance its visual texture. Diffused lighting deemphasizes physical texture and can even obscure its three-dimensional structure.

Smooth, shiny surfaces reflect light brilliantly, appear sharply in focus, and attract our attention. Surfaces with a matte or medium-rough texture absorb and diffuse light unevenly and, therefore, appear less bright than similarly colored but smoother surfaces. Very rough surfaces, when illuminated with direct lighting, cast distinct shadow patterns of light and dark.

Figure (top) depicting the light flashed on textures. The arrows drawn on the textures are denoting the direction of lighting. Figure (bottom) depicting the effect of light on the textures, where shiny surfaces reflect while matte surfaces diffuse the light.

Figure depicting the effect of contrast that affects the apparent strength or subtlety of adjacent textures. — Contrast affects the apparent strength or subtlety of adjacent textures.

Contrast influences how strong or subtle a texture will appear to be. A texture seen against a uniformly smooth background will appear more obvious than when placed in juxtaposition with a similar texture. When seen against a coarser background, the texture will appear to be finer and reduced in scale.

Finally, texture is a factor in the maintenance of the materials and surfaces of a space. Smooth surfaces show dirt and wear but are relatively easy to clean, while rough surfaces may conceal dirt but may also be more difficult to maintain.

Texture can also result from the manner in which materials are assembled in construction.

Texture and pattern are closely related design elements. Pattern is the decorative design or ornamentation of a surface that is almost always based on the repetition of a motif—a distinctive and recurring shape, form, or color in a design. The repetitive nature of a pattern often gives the ornamented surface a textural quality as well. When the elements that create a pattern become so small that they lose their individual identity and blend together, they become more texture than pattern.

A pattern may be integral or applied. An integral pattern results from the intrinsic nature of a material and the way it is processed, fabricated, or assembled. An applied pattern is added to a surface after it is fabricated or built.

Figure depicting the textures formed by the reduction in its pattern. — A pattern reduced in scale becomes texture.

Figure depicting the examples of integral and applied patterns.

Figure depicting the examples of minimal texture, textured, texture filling space, and competing textures.

Texture is an intrinsic characteristic of the materials we use to define, furnish, and embellish interior space. How we combine and compose differing textures is just as important as the composition of color and light, and should suit the desired character and use of a space.

The scale of a textural pattern should be related to the scale of a space and its major surfaces, as well as to the size of secondary elements within the space. Since texture tends to visually fill space, any textures used in a small room should be subtle or used sparingly. In a large room, texture can be used to reduce the scale of the space or to define a more intimate area within it.

A room with little textural variation can be bland. Combinations of hard and soft, even and uneven, and shiny and dull textures can be used to create variety and interest. In the selection and distribution of textures, moderation should be exercised and attention paid to their ordering and sequence. Harmony among contrasting textures can be sustained if they share a common trait, such as degree of light reflectance or visual weight.

Figure depicting a view of a room with increasing textures from left to right. — Increasing textures in a room from left to right

A plane extended in a direction other than along its surface forms a volume. Conceptually and in reality, a volume exists in three dimensions.

Form is the term we use to describe the contour and overall structure of a volume. The specific form of a volume is determined by the shapes and interrelationships of the lines and planes that describe its boundaries.

As the three-dimensional element of architectural and interior design, a volume can be either a solid (space displaced by the mass of a building or building element) or a void (space contained and defined by wall, floor, and ceiling or roof planes). It is important to perceive this duality of containment versus displacement, especially when reading orthographic plans, elevations, and sections.

Figure depicting the examples of form, space, and form and space both.

The duality of solid forms and spatial voids represents the essential unity of opposites that shapes the reality of architecture and interior design. Visible forms give space dimension, scale, color, and texture, while space reveals the forms. This symbiotic relationship between form and space can be seen at several scales in interior design.

Figure depicting an example of forms in space.

Color, like shape and texture, is an inherent visual property of all form. We are surrounded by color in our environmental settings. The colors we attribute to objects find their source in the light that illuminates and reveals form and space. Without light, color does not exist.

The science of physics deals with color as a property of light. Within the visible spectrum of light, color is determined by wavelength. Starting at the longest wavelength with red, we proceed through the spectrum of orange, yellow, green, blue, and violet to arrive at the shortest visible wavelengths. When these colored lights are present in a light source in approximately equal quantities, they combine to produce white light—light that is apparently colorless.

Research suggests that humans exposed to the same colors tend to see colors in similar ways. This may allow people with very different eyes to see colors in similar ways. It can also result in people in very different environments perceiving colors differently.

As people age, the lens of the eye becomes more yellow. By age 70, most people see the world through a lens roughly the color of ginger ale, especially when distinguishing between blues and purples. Using rich, saturated colors and plentiful lighting helps. Aging may also increase the incidence of cataracts, which causes the eye's lens to turn cloudy with a yellowish, brownish tint; macular degeneration, which blurs central vision and makes objects less bright; and the effects of glaucoma or dementia.

Avoiding contrast on surfaces like walls and floors helps clients avoid seeing them as holes that could cause a misstep or fall. Yellow color schemes may be avoided because of the effects of cataracts. Rather than avoiding specific colors, designing with the whole spectrum of the outdoors may be a better choice.

Sensitivity to glare appears to increase as we age, so a matte or lower sheen may be a better approach than a high gloss. And, as is usually the case, testing a potential color with a variety of natural and artificial light sources is a good idea.

In northern climates, the red and orange end of full-spectrum daylight is partially blocked, while the blue end passes through, making some paint colors appear greenish.

Figure depicting an example of colored texture.

Figure depicting an example of electromagnetic spectrum, where visible white light splits into its constituents colors when passed through a prism.

Figure depicting an example of light reflection, where a beam of white light (consisting 7 colors) reflects from a red surface. The reflected light is reddish in which red component dominates.

Three intersecting circles depicting an example of colored lights that combine by additive mixing. — Colored lights combine by additive mixing.

Figure depicting an example of pigment colors that combine by subtractive mixing. — Pigment colors combine by subtractive mixing.

When white light falls on an opaque object, selective absorption occurs. The surface of the object absorbs certain wavelengths of light and reflects others. Our eyes apprehend the color of the reflected light as the color of the object.

White light is composed of the entire spectrum of colored lights. Some light sources—such as some electric lamps or light reflected off a colored wall—may not be well balanced and thus lack part of the spectrum. This lack of certain colors will make a surface illuminated by such light appear to lack those colors.

Artificial lighting has its own color bias. LED light tends to be whiter and more neutral than other sources, but can be programmed for different wavelengths and intensity. Fluorescent bulbs produce a cool blue light, while incandescent bulbs shift light color toward a warm orange.

Which wavelengths or bands of light are absorbed and which are reflected as object color is determined by the pigmentation of a surface. A red surface appears red because it absorbs most of the blue and green light falling on it and reflects the red part of the spectrum; a blue surface absorbs the reds. Similarly, a black surface absorbs the entire spectrum; a white surface reflects all of it.

A surface has the natural pigmentation of its material. This coloration can be altered with the application of paints, stains, or dyes that contain color pigments. While colored light is additive in nature, color pigments are subtractive. Each pigment absorbs certain proportions of white light. When pigments are mixed, their absorptions combine to subtract various colors of the spectrum. The colors that remain determine the hue, value, and intensity of the mixed pigment.

It is important for interior designers to remember that the colors they see on their computer screens are colored light, while colors in printed materials and samples are pigments. For accuracy, they should rely on physical color samples viewed in the light in which they will be used.

Color has three dimensions:

Hue

The attribute by which we recognize and describe a color, such as red or yellow.

Value

The degree of lightness or darkness of a color in relation to white and black.

Saturation

The brilliance or dullness of a color; this depends on the amount of hue in a color.

All of these attributes of color are interrelated. Each principal hue has a normal value. Pure yellow, for example, is lighter in value than pure blue. If white, black, or a complementary hue is added to a color to lighten or darken its value, its saturation will be diminished as well. It is difficult to adjust one attribute of a color without simultaneously altering the other two.

A number of color systems attempt to organize colors and their attributes into a visible order. The simplest type, such as the Brewster/Prang color wheel, organizes color pigments into primary, secondary, and tertiary hues.

The primary hues are red, yellow, and blue. The secondary hues are orange, green, and violet. The tertiary hues are red-orange, yellow-orange, yellow-green, blue-green, blue-violet, and red-violet.

Figure depicting the three dimension of colors: hue, value, and saturation.

Figure (top) depicting Munsell color wheel. Figure (bottom) depicting Munsell color space, where hue, value scale, and chroma are labeled.

With the advent of color computer monitors and printers, the need for a universal language of color communication has become even more pressing. Interior designers often must indicate a color to be used uniformly in paints, textiles, graphic design materials, and other media.

Commission Internationale de l'Eclairage (CIE) standards are based on the precise measurement of light waves reflected by a surface, factored by sensitivity curves that have been measured for the human eye. Although cumbersome to use, CIE standards are specified by most U.S. furniture manufacturers.

Color maps, such as the color space developed by Munsell and described earlier, allow color communication between any two individuals with the same map.

Systems such as Pantone^® for architecture and interiors provide the interior designer with a way to specify, communicate, and manage color choices for a wide variety of materials, both online and offline.

Other available tools are electronic color analyzers, which identify color data from samples, and color viewing lights, which simulate varied lighting conditions. Electronic color analysis is commonly used for paint matching. Color may be mixed at the point of sale to match almost any color sample.

Figure depicting CIE chromaticity diagram.

Figure depicting a sampling of Pantone® color swatches.

Object colorants, such as paints and dyes, are means to modify the color of the illuminating light, changing what we interpret to be the color of the object. In mixing the pigments of paints and dyes, each of the attributes of color can be altered.

The hue of a color can be changed by mixing it with other hues. When neighboring or analogous hues on the color wheel are mixed, harmonious and closely related hues are created. In contrast to this, mixing complementary hues, those hues directly opposite each other on the color wheel, produces neutral hues.

The value of a color can be raised by adding white and lowered by adding black. Lightening a hue's normal value by adding white creates a tint of that hue; darkening the hue's normal value with black creates a shade of the hue. A normally high-value color, such as yellow, is capable of more shades than tints, while a low-value color, such a red, is able to have more tints than shades.

The intensity of a color can be strengthened by adding more of the dominant hue. It can be lowered by mixing gray with the color or by adding to the color its complementary hue. Hues that are grayed or neutralized in this manner are often called tones.

Apparent changes in an object's color can result from the effects of light and from the juxtaposition of surrounding or background colors. These factors are especially important to the interior designer, who must carefully consider how the colors of elements in an interior space interact and how they are rendered by the light illuminating them.

Light of a particular hue, other than white, is rarely used for general illumination. However, not all sources of what we consider white light are spectrally well balanced. Incandescent bulbs cast a warm glow, while some fluorescents cast a cool light. Even the color of a large reflecting surface can alter the light within an interior space. The current widening use of LED light encourages the use of colored light in interiors. It is important to be aware that colored light changes the color of the object it is reflected from. For example, an appealing red apple can become a very unappealing gray one. It requires foresight and care to avoid negative effects when using colored light. Observing color firsthand, taking into account the sun's angle and direction along with the amount and quality of artificial light, is the surest way to verify what a color will actually look like.

Daylight, too, can be warm or cool, depending on the time of day and the direction from which it comes. The color of sunlight throughout the day changes color perception. Human eyes have evolved to see better during the day than night, and our brains adjust to figure out what color we are really observing (our chromatic bias). Morning and evening have an orange bias, and midday light under a clear sky has a blue bias. Our brains automatically shift by subtracting the prevailing bias as the quality and angle of light changes. Rapid changes in light during transition periods from dawn to early morning and from twilight and dusk to dark can throw off this adjustment. These times of day are the worst times to make color decisions and should be avoided when choosing colors indoors. However, our brains do take prior experience into consideration. Observing what happens when window blinds are opened and closed also helps. Warm light tends to accentuate warm colors and neutralize cool hues, while cool light intensifies cool colors and weakens warm hues. If light is altered with a particular hue, it will raise the intensity of colors of that hue and neutralize colors of a complementary hue.

The apparent value of a color can also be altered by the amount of light used to illuminate it. Lowering the amount of illumination will darken a color's value and neutralize its hue. Raising the lighting level will lighten the color's value and enhance its intensity. However, high levels of illumination can also tend to make colors appear less saturated, or washed out.

The natural fluctuations of light in an interior setting can alter colors in subtle ways. A color may also look different depending on its angle to the viewer. It is always best to test colors in the environment in which they are to be viewed, under both daylight and nighttime conditions.

Figure (top) depicting the conditions (daylight and artificial light) affecting the rendition of colors in an interior space. An example of strong illumination, medium illumination, and low illumination are depicted at the bottom. — Conditions affecting the rendition of colors in an interior space.

Analogous colors push each other toward the other's complement.

Although mixing two complementary color pigments results in a neutralized or grayed hue, placing them next to each other can produce the opposite effect. In the phenomenon known as simultaneous contrast, the eye tends to generate a color's complementary hue and project it as an afterimage on adjacent colors. Thus, two complementary colors placed side by side tend to heighten each other's saturation and brilliance without an apparent change in hue.

When the two colors are not complementary, each will alter the other with its own complement and shift it toward that hue. The result is that the two colors are pushed farther apart in hue.

Simultaneous contrast in hue is most easily perceived when two colors are fairly uniform in value. If one color is much lighter or darker than the other, the effects of contrasting values become more noticeable.

Simultaneous contrast also affects the apparent value of a color, which can be made to appear lighter or darker according to the value of its background color. A light color will tend to deepen a dark color, while a dark color will tend to brighten a light color.

Both black and white have a visible effect on colors brought into contact with them. Surrounding colors with black tends to make them richer and more vibrant, while outlining with white often has the opposite effect. A large area of white will reflect light onto adjacent colors, while thin white lines tend to spread and alter the hues they separate.

The effects of contrasting hues and values depend on areas large enough to be perceived as separate colors. If the areas are small and closely spaced, the eye does not have enough time to adjust to their differences and mixes the colors optically. The effects of optical mixing are often used in the weaving of textiles to create an impression of many hues and values with a limited number of colored yarns or threads.

Figure depicting an example of contrasting values alter perceived values. — Contrasting values alter perceived values.

Figure depicting an example of optical mixing that occurs when dots or strokes of colors merge to produce more blended hues. — Optical mixing occurs when dots or strokes of colors merge to produce more blended hues.

In addition to understanding how colors interact and alter one another's attributes, the interior designer must consider how color affects our perception of form and the dimensions and qualities of interior space.

Colors are often divided into warm and cool categories. Reds, oranges, and yellows are considered to be warm colors that advance. Blues, greens, and violets are considered cooler and tend to recede. Neutrals, such as grays and off-whites, may be either warm (brownish) or cool (bluish).

The warmth or coolness of a color's hue, along with its relative value and degree of saturation, determines the visual force with which it attracts our attention, brings an object into focus, and creates a sense of space. The following generalizations summarize some of these effects of color.

Warm hues and high intensities are said to be visually active and stimulating, while cool hues and low intensities are more subdued and relaxing. Light values tend to be cheerful, middle values undemanding, and dark values somber.

Bright, saturated colors and any strong contrasts attract our attention. Grayed hues and middle values are less forceful. Contrasting values, in particular, make us aware of shapes and forms. Contrasting hues and saturations can also define shape, but if they are too similar in value, the definition they afford will be less distinct.

Figure depicting value contrast aids in our perception of shape. — Value contrast aids in our perception of shape.

Deep, cool colors appear to contract. Light, warm colors tend to expand and increase the apparent size of an object, especially when seen against a dark background.

When used on an enclosing plane of a space, light values, cool hues, and grayed colors appear to recede and increase apparent distance. They can therefore be used to enhance the spaciousness of a room and increase its apparent width, length, or ceiling height.

Warm hues appear to advance. Dark values and saturated colors suggest nearness. These traits can be used to diminish the scale of a space or, in an illusory way, shorten one of a room's dimensions. These color generalizations have complex interrelationships. For example, although blue is considered cool and red warm, a vibrant electric blue may not strike us as cooler than a soft rose. Our emotional reactions to color vary with our personal experiences and cultural associations. In addition, favored color combinations are subject to fashion trends, with certain color palettes closely tied to specific times or places.

Research into the effects of color in workspaces has shown that white, although crisp and clean, does not aid productivity. Red aids detail-oriented workers, and can raise blood pressure, speed up respiration and heartbeat, and increase alertness. Blue aids creativity, and green inspires innovation. Women have an extra gene that makes it possible to detect more variations in the red-orange spectrum than men. Experts recommend avoiding yellow in conference rooms as well as the suppressive impact of gray.

Although vibrant colors and patterns can be used to create a lively environment, too much can produce visual chaos. Instead, less obtrusive natural colors can be used in unobtrusive patterns to create a floor, for example, that echoes cobblestones or wood grains.

The effect of values on spatial boundaries

Figure depicting color scheme, where intensity, value, and hue are labeled in the figure.

Monochromatic color schemes vary the value of a single hue.

Analogous color schemes use two or more hues from the same quarter of the color wheel.

Complementary color schemes use two hues on opposite sides of the color wheel.

Split complementary color schemes combine one hue with the two hues adjacent to its complement.

Triadic color schemes use colors located at three equidistant points on the color wheel.

Contrasting hue schemes are based on complementary or triadic color combinations.

Although each of us may have favorite colors and a distinct dislike of others, there is no such thing as a good or bad color. Some colors are simply in or out of fashion at a given time; others may be appropriate or inappropriate given a specific color scheme. The suitability of a color depends ultimately on how and where it is used and how it fits into the palette of a color scheme.

Digital mobile color scanning tools are now available that aid in the management, organization, and sharing of a color specification. In addition, videoconferencing systems using wireless projection allow seamless video communication across any device with a screen via cloud-based service, saving money and equipment. With an Internet connection available, everyone can contribute to the conversation from wherever they are.

Manufacturers design color series for paints that suggest compatible color selections. These series may be scientifically built on gradations of pigments; based on references to nature, fabrics, or other materials; or developed to reflect emotional, historic, or similar associations.

If colors are like the notes of a musical scale, then color schemes are like musical chords, structuring color groups according to certain visual relationships among their attributes of hue, value, and intensity. The color schemes shown here are based on the hue relationships within a color group.

There are two broad categories of hue schemes, related and contrasting. Related hue schemes, based on either a single hue or a series of analogous hues, promote harmony and unity. Variety can be introduced by varying value and intensity, by including small amounts of other hues as accents, or by bringing shape, form, and texture into play.

Contrasting hue schemes, based on complementary or triadic color combinations, are inherently more rich and varied, since they always include both warm and cool hues.

Hue schemes merely outline the approaches one can take in organizing a combination of hues. In designing a color scheme, other color relationships must also be considered.

The color triangle developed by Faber Birren illustrates how modified colors—tints, tones, and shades—may be related in a harmonious sequence. The triangle is based on the three basic elements: pure color, white, and black. They combine to create the secondary forms of tint, shade, gray, and tone. Any of the bold-line paths illustrated here define a harmonious sequence, since each involves a series of visually related elements.

Ultimately, whether a color scheme is lively and exuberant or restful and quiet will depend on the chromatic and tonal values of the hues chosen. Large intervals between the colors and values will create lively contrasts and dramatic effects. Small intervals will result in more subtle contrasts and patterns.

Figure depicting the examples for small (top) and large intervals between the colors.

Figure depicting the chromatic distribution of colors.

Large areas of intense color can be both dramatic and visually demanding.

In developing a color scheme for an interior space, one must consider carefully the chromatic and tonal key to be established and the distribution of the colors. The scheme must not only satisfy the purpose and use of the space but also take into account its architectural character.

Decisions must be made regarding the major planes of an interior space and how color might be used to modify their apparent size, shape, scale, and distance. Which elements will form the background, middle ground, and foreground? Are there architectural or structural features that should be accentuated, or undesirable elements to be minimized?

Usually, the largest surfaces of a room—its floor, walls, and ceiling—have the most neutral values. Against this background, secondary elements such as large pieces of furniture or area rugs can have greater chromatic intensity. Finally, accent pieces, accessories, and other small-scale elements can have the strongest chroma for balance and to create interest.

Neutral color schemes are the most flexible. For a more dramatic effect, the main areas of a room can be given the more intense values, while secondary elements have lesser intensity. Large areas of intense color should be used with caution, particularly in a small room. They reduce the apparent distance and can be visually demanding.

Sketch depicting the balancing of large neutral areas with smaller areas of stronger intensity. — Balance large neutral areas with smaller areas of stronger intensity.

Of equal importance to chromatic distribution is tonal distribution, the pattern of lights and darks in a space. It is generally best to use varying amounts of light and dark values with a range of middle values to serve as transitional tones. Avoid using equal amounts of light and dark unless a fragmented effect is desired.

Figure depicting the tonal distribution of colors.

Figure depicting the visual relationships that established among the interior design elements in a space are ordered by proportion, scale, balance, harmony, unity and variety, rhythm, and emphasis.

Interior design involves the selection of interior design elements and their arrangement within a spatial enclosure to satisfy functional and aesthetic requirements. This arrangement of elements in a space involves pattern making. No one single part or element in a space stands alone. In a design pattern, all of the parts, elements, or pieces depend on one another for their visual impact, function, and meaning.

The visual relationships established among the interior design elements in a space are ordered by proportion, scale, balance, harmony, unity and variety, rhythm, and emphasis. These design principles are not intended to be hard and fast rules, but rather guidelines to the possible ways design elements can be arranged into recognizable patterns. Ultimately, we must learn to judge the appropriateness of a pattern, its visual role in a space, and its meaning to the users of the space. These principles, however, can help develop and maintain a sense of visual order among the design elements of a space, while accommodating their intended use and function.

Proportion refers to the relationship of one part to another or to the whole, or between one object and another. This relationship may be one of magnitude, quantity, or degree.

When dealing with forms in space, one must consider proportion in three dimensions.

The apparent size of an object is influenced by the relative sizes of other objects in its environment.

In the course of history, a number of mathematical or geometric methods have been developed to determine the ideal proportion of things. These proportioning systems go beyond functional and technical determinants in an attempt to establish a measure of beauty—an aesthetic rationale for the dimensional relationships among the parts and elements of a visual construction.

According to the ancient Greek mathematician Euclid, a ratio refers to the quantitative comparison of two similar things, while proportion refers to the equality of ratios. Underlying any proportioning system, therefore, is a characteristic ratio, a permanent quality that is transmitted from one proportion to another.

Perhaps the most familiar proportioning system is the golden section established by the ancient Greeks. It defines the unique relationship between two unequal parts of a whole in which the ratio between the smaller and greater parts is equal to the ratio between the greater part and the whole.

The Fibonacci series is a progression of whole numbers wherein each term is the sum of the preceding two. The ratio between two consecutive terms approximates the golden section.

Although often defined in mathematical terms, a proportioning system establishes a consistent set of visual relationships among the parts of a composition. It can be a useful design tool for promoting unity and harmony. However, our perception of the physical dimensions of things is often imprecise. The foreshortening of perspective, viewing distance, or even cultural bias can distort our perception.

The matter of proportion is primarily one of critical visual judgment. In this respect, significant differences in the relative dimensions of things are important. Ultimately, a proportion will appear to be correct for a given situation when we sense that neither too little nor too much of an element or characteristic is present.

Figure depicting the forms of some shapes that vary significantly in their proportions. — These forms vary significantly in their proportions.

Figure depicting two chairs that differ significantly in their proportions. — Pieces of furniture may differ significantly in their proportions.

Figure depicting two tables in which one is thin while the other one is heavy. — Diagonals that are parallel or perpendicular to each other indicate that the rectangles they bisect have similar proportions.

In interior design, we are concerned with the proportional relationships between the parts of a design element, between several design elements, and between the elements and the spatial form and enclosure.

Figure depicting the proportion differences between tables, sofas, and parts of an element.

Figure (top) depicting the proportion difference between elements. Figure (bottom) depicting a sketch where main emphasis and counterpoint are labeled. — Between elements

Figure depicting the proportion difference between elements and the spatial enclosure. — Between elements and the spatial enclosure

The design principle of scale is related to proportion. Both proportion and scale deal with the relative sizes of things. If there is a difference, proportion pertains to the relationships between the parts of a composition, while scale refers specifically to the size of something, relative to some known standard or recognized constant.

Mechanical scale is the calculation of something's physical size according to a standard system of measurement. For example, we can say that a table is, according to the U.S. Customary System, 3 feet wide, 6 feet long, and 29 inches high. If we are familiar with this system and with objects of similar size, we can visualize how big the table is. Using the International System of Units (the metric system), the same table would measure 914 mm wide, 1829 mm long, and 737 mm high.

Figure depicting a table, where a person, whose length is similar to the table, is measuring the length of the table by his hands. A lady is standing nearby the table. — Our bodies can serve as a system of measurement.

A sketch depicting a table of 3 feet wide, 6 feet long, and 29 inches high. — **Mechanical Scale** Size relative to an accepted standard of measurement

Figure (top) depicting an example of small scale by a set of two sofas and one chair. Figure (middle) depicting an example of large scale by a set of one sofa and two chairs. Figure (bottom) depicting small-scale space or large-scale furniture. — Small-scale space or large-scale furniture

**Visual Scale** Size relative to other objects in the environment or to the surounding space

Visual scale refers to the size something appears to have when measured against other things around it. Thus, an object's scale is often a judgment we make based on the relative or known sizes of nearby or surrounding elements. For example, the aforementioned table can appear to be in scale or out of scale with a room, depending on the relative size and proportions of the space.

We can refer to something as being small scale if we are measuring it against other things that are generally much larger. Similarly, an object can be considered to be large scale if it is grouped with relatively small items, or if it appears to be larger than what is considered normal or average.

Human scale refers to the feeling of bigness something gives us. If the dimensions of an interior space or the sizes of elements within it make us feel small, we can say they lack human scale. If, on the other hand, the space does not dwarf us, or if the elements offer a comfortable fit with our dimensional requirements of reach, clearance, or movement, we can say they are human in scale.

Most of the elements we use to ascertain human scale are those whose dimensions we have become accustomed to through contact and use. These include doorways, stairs, tables, counters, and various types of seating. These elements can be used to humanize a space that would otherwise lack human scale.

Interior details near eye level can be used to bring the scale of an architectural space down to human size. For example, a chair rail along a wall creates a visual line at roughly hand height. Similarly, moderately scaled artwork and accessories can help make an imposing space feel more comfortable.

We can judge the scale of a space by the relative size of the interior elements within it.

We often use doorways, windowsills, tables, and chairs to discern human scale because we have become accustomed to their dimensions.

A sketch depicting cups on the table, a sofa, and a chair.

**Human Scale** The feeling of smallness or bigness a space or an interior element gives us.

The issue of scale in an interior space is not limited to one set of relationships. Interior elements can be related simultaneously to the whole space, to each other, and to those people who use the space. It is not unusual for some elements to have a normal, orderly scale relationship but have an exceptional scale when compared to other elements. Unusually scaled elements can be used to attract attention or create and emphasize a focal point.

Figure depicting an example of scale relationship. — A set of scale relationships can exist within a larger context.

Doorways and windows may be scaled to the dimensions of a space while sill heights and wainscots retain a human scale.

Interior spaces—and their elements of enclosure, furnishings, lighting, and accessories—often include a mix of shapes, sizes, colors, and textures. The organization of these elements is a response to functional needs and aesthetic desires. At the same time, these elements should be arranged to achieve visual balance—a state of equilibrium among the visual forces projected by the elements.

Each element in the ensemble of interior space has specific characteristics of shape, form, size, color, and texture. These characteristics, along with the factors of location and orientation, determine the visual weight of each element and how much attention each will attract in the overall pattern of space.

Characteristics that will enhance or increase the visual weight of an element—and attract our attention—include:

Irregular or contrasting shapes
Bright colors and contrasting textures
Large dimensions and unusual proportions
Elaborate details

Attracting attention with …

Figure depicting the interiors: a mix of shapes, colors, and textures, irregular shapes, and contrasting textures. — Interiors: A mix of shapes, colors, and textures

Figure depicting an example of unusual proportions and elaborate details.

Our perception of a room, and the composition of its elements, is altered as we use it and move through its space. Our perspective varies as our point of view shifts from here to there. A room also undergoes changes as it is illuminated by the light of day and by lighting fixtures at night, occupied by people and paraphernalia, and modified over time. The visual balance among the elements in a space should therefore be considered in three dimensions and be strong enough to withstand the changes brought about through time and use.

A sketch (top) depicting a room and the composition of its elements. A sketch (bottom) depicting a room and the composition of its elements in three dimensions.

Visual balance must be considered in three dimensions.

There are three types of visual balance: symmetrical, radial, and asymmetrical. Symmetrical balance results from the arrangement of identical elements, corresponding in shape, size, and relative position, about a common line or axis. It is also known as axial or bilateral symmetry.

Symmetrical balance most often results in a quiet, restful, and stable equilibrium that is readily apparent, especially when oriented on a vertical plane. Depending on its spatial relationships, a symmetrical arrangement can either emphasize its central area or focus attention on the terminations of its axis.

A sketch of interior part of a house focuses on the middle ground. — Focus on the middle ground.

A sketch of interior part of a house focuses on the termination of an axis. — Focus on termination of an axis

Symmetry is a simple yet powerful device to establish visual order. If carried far enough, it can impose a strict formality on an interior space. Total symmetry, however, is often undesirable or difficult to achieve because of function or circumstance.

It is often possible or desirable to arrange one or more parts of a space in a symmetrical manner and produce local symmetry. Symmetrical groupings within a space are easily recognized and have a quality of wholeness that can serve to simplify or organize the room's composition.

The second type of balance, radial balance, results from the arrangement of elements about a center point. It produces a centralized composition that stresses the middle ground as a focal point. The elements can focus inward toward the center, face outward from the center, or simply be placed about a central element.

A sketch of interior part of a house depicting local symmetry.

Asymmetry is recognized as the lack of correspondence in size, shape, color, or relative position among the elements of a composition. While a symmetrical composition requires the use of pairs of identical elements, an asymmetrical composition incorporates dissimilar elements.

To achieve an occult or optical balance, an asymmetrical composition must take into account the visual weight or force of each of its elements and employ the principle of leverage in their arrangement. Elements that are visually forceful and attract our attention—unusual shapes, bright colors, dark values, variegated textures—must be counterbalanced by less forceful elements that are larger or placed farther away from the center of the composition.

Asymmetrical balance is not as obvious as symmetry and is often more visually active and dynamic. It is capable of expressing movement, change, even exuberance. It is also more flexible than symmetry and can adapt more readily to varying conditions of function, space, and circumstance.

Harmony can be defined as consonance, or the pleasing agreement of parts or combination of parts in a composition. While balance achieves unity through the careful arrangement of both similar and dissimilar elements, the principle of harmony involves the careful selection of elements that share a common trait or characteristic, such as shape, color, texture, or material. It is the repetition of a common trait that produces unity and visual harmony among the elements in an interior setting.

Figure depicting an example of harmony. The examples of a common size, similar colors and values, a common shape, similar materials, a similar orientation, and similar detail characteristics are depicted.

Harmony, when carried too far in the use of elements with similar traits, can result in a unified but uninteresting composition. Variety, on the other hand, when carried to an extreme for the sake of interest, can result in visual chaos. It is the careful and artistic tension between order and disorder—between unity and variety—that enlivens harmony and creates interest in an interior setting.

It is important to note that the principles of balance and harmony, in promoting unity, do not exclude the pursuit of variety and interest. Rather, the means for achieving balance and harmony are intended to include in their patterns the presence of dissimilar elements and characteristics.

For example, asymmetrical balance produces equilibrium among elements that differ in size, shape, color, or texture. The harmony produced by elements that share a common characteristic permits the same elements to also have a variety of unique, individual traits.

Another method for organizing a number of dissimilar elements is to arrange them in close proximity to one another. We tend to read such a grouping as an entity, to the exclusion of other elements farther away. To further reinforce the visual unity of the composition, continuity of line or contour can be established among the elements' shapes.

A sketch depicting asymmetrical schemes that organize a variety of shapes, colors, and textures into their layouts. — Asymmetrical schemes can organize a variety of shapes, colors, and textures into their layouts.

Figure depicting foreground elements organized by a common backdrop and dissimilar elements organized by grouping in close proximity or by relating to a common line or plane. — Dissimilar elements can be organized by grouping them in close proximity or by relating them to a common line or plane.

A sketch depicting an example of background rhythm for foreground elements or in defining a textured line, border, or trim.

Figure depicting the repetitive nature of structural elements that creates a natural rhythm in three dimensions. — The repetitive nature of structural elements creates a natural rhythm in three dimensions.

The design principle of rhythm is based on the repetition of elements in space and time. This repetition not only creates visual unity but also induces a recurring continuity of movement that a viewer's eyes and mind can follow along a path, within a composition, or around a space.

The simplest form of repetition consists of the regular spacing of identical elements along a linear path. Although this pattern can be quite monotonous, it can also be useful in establishing a background rhythm for foreground elements or in defining a textured line, border, or trim.

More intricate patterns of rhythm can be produced by taking into account the tendency for elements to be visually related by their proximity to one another or their sharing of a common trait.

The spacing of the recurring elements, and thus the pace of the visual rhythm, can be varied to create sets and subsets and to emphasize certain points in the pattern. The resulting rhythm may be graceful and flowing or crisp and sharp. The contour of the rhythmic pattern and the shape of the individual elements can further reinforce the nature of the sequence.

Although the recurring elements must, for continuity, share a common trait, they can vary in shape, detail, color, or texture. These differences, whether subtle or distinct, create visual interest and can introduce other levels of complexity. An alternating rhythm can be superimposed over a more regular one, or the variations can be progressively graded in size or color value to give a direction to the sequence.

A sketch depicting rhythm that exists at the detail level. — Rhythm existing at the detail level

Figure depicting the detail variations in rhythm: gradation in value or color and gradation in size.

Visual rhythm is most easily recognized when the repetition forms a linear pattern. Within an interior space, however, nonlinear sequences of shape, color, and texture can provide subtler rhythms that may not be immediately obvious to the eye.

Figure depicting an example of contrasting rhythms and background rhythm.

Figure depicting an example of vertical, layered, and foreground rhythms.

Rhythm may refer to the movement of our bodies as we advance through a sequence of spaces. Rhythm incorporates the fundamental notion of repetition as a device to organize forms and spaces in architecture. Beams and columns repeat themselves to form repetitive structural bays and modules of space. Spaces often recur to accommodate similar or repetitive functional requirements in the building program.

Figure depicting an example of structural rhythm and rhythm connecting points in space. — Rhythm connecting points in space

Figure depicting an example of vertical and horizontal rhythms and the manner in which stairways and railings express movement naturally results in rhythmic patterns. — Vertical and horizontal rhythms

The principle of emphasis assumes the coexistence of dominant and subordinate elements in the composition of an interior setting. A design without any dominant elements would be bland and monotonous. If there are too many assertive elements, the design will be cluttered and chaotic, detracting from what may be important. Each part of a design should be given proper significance according to its degree of importance in the overall scheme.

An important element or feature can be given visual emphasis by endowing it with significant size, a unique shape, or a contrasting color, value, or texture. In each case, a discernible contrast must be established between the dominant element or feature and the subordinate aspects of the space. Such contrast will attract our attention by interrupting the normal pattern of the composition.

Points of emphasis can be created by a perceptible contrast in size, shape, color, or tonal value.

Figure depicting an example of exceptional shape of a building.

An element or feature can also be visually emphasized by its strategic position and orientation in a space. It can be centered within the space or serve as the centerpiece of a symmetrical organization. In an asymmetric composition, it can be offset or isolated from the rest of the elements. It can be the termination of a linear sequence or a path of movement.

To further enhance its visual importance, an element can be oriented to contrast with the normal geometry of the space and the other elements within it. It can be illuminated in a special manner. The lines of secondary and subordinate elements can be arranged to focus our attention on the significant element or feature.

Some strategies for creating emphasis when using lighting and color together include:

String rope lighting in or around a ceiling to add dimension and lighten darker hues.
Suspend eye-catching pieces in a tall, colorful lobby to emphasize its height.
Use smaller, separate light fixtures to create individual spaces.

Figure depicting the points of emphasis created by the strategic positioning of important elements. — Points of emphasis can be created by the strategic positioning of important elements.

Figure depicting shift in geometry, spotlighted, center of focus, and termination of axis.

Just as there may be varying degrees of importance among the elements in an interior setting, there can also be varying degrees of emphasis. Once the significant elements or features are established, a strategy for orchestrating the subordinate elements must be devised to enhance the dominant ones.

A room's focal points should be created with some subtlety and restraint. They should not be so visually dominant that they cease to be integral parts of the overall design. Secondary points of emphasis—visual accents—can often help knit together dominant and subordinate elements. Following the principle of harmony, related shapes, colors, and values can also help retain unity of design.