What we identify as color is really just the perception by our eyes and brains of the spectrum of light and its interaction with objects and materials. The perception of color also varies by individual and by species. Those who are colorblind lack the ability to see certain colors or to distinguish between colors. Dogs and cats see in color, but they can’t see all the colors that their human companions do. As a symbol, color plays a central role in almost everything we do, from singing the blues to stopping at red lights.
Humans have always used color as a form of expression, the earliest evidence of which is cave paintings from the Paleolithic era. The ancient Egyptians used color to represent specific characteristics. For instance, Osiris, the god of the afterlife, the underworld, and the dead, is always depicted with green skin—the color of rebirth. Many of the ancient Greek and Roman statues carved in white marble that survived to the present day—such as the Lovatelli Venus from the first century C.E.—once bore bright paint colors that wore off over time. Color also plays an important role in religion. In Christianity, for example, purple is associated with penance and is used during the seasons of Advent and Lent.
There are many fields that feature color symbolism. Color psychology, for instance, is the study of how color affects human behavior. Professionals in this field have made fascinating discoveries and even instituted changes based on color that have improved our daily lives. For example, based on evidence that the color blue has a calming effect, in 2000, the city of Glasgow, Scotland, instituted blue streetlights in certain areas and found that crime decreased as a result.