The goal of color management tools is to ensure that the colors in your artwork are correctly translated between different output devices, most often from screen to print. The ranges of colors that can be reproduced are different for different devices, and some color distortions are unavoidable. Color management allows you to preview, control, and thereby minimize these distortions.
In Inkscape, color management is a developing area, and it is still in a quite primitive state. You can use screen proofing to preview output colors; however, using Inkscape alone, you cannot properly prepare a file for print (i.e., color-separate it and save it with a color profile embedded). However, in most cases you can get the result you need by using some tricks and employing some additional software, as described in this section.
However, before you go into it, consider if you really need color management. If you are going to print your art on a desktop color printer, chances are its quality is simply not good enough for color management to make a significant difference. A typical desktop printer will accept and print the same RGB data as is displayed on your screen, performing its own color conversion without bothering the user.
The need for color management arises when you are going to print your documents using a professional printer, e.g., by sending them to a print service provider. Even then, some providers will perform color management on your documents for you if you ask them to. If you have sufficient control over this process (for example, can review the print proofs), this is usually the best option because the print service staff knows what works best with their equipment.
An ICC color profile is a file that fully describes the color capabilities of an output device. If you want to prepare your document for outputting on a specific device, you must first obtain the ICC profile that exactly corresponds to this device and the output media (for example, paper type used for printing). Sometimes, you can find an appropriate profile file on the Internet (for example, on the web site of the printer hardware’s manufacturer); sometimes, you can request them from the print service provider you will be using. A useful package of generic profiles can be obtained from Adobe at http://www.adobe.com/downloads.
Once you get the destination profile, put it into ~/.local/share/color/icc on Linux and system32\spool\drivers\color inside the Windows folder on Windows.
Since the color range of a typical printer is narrower than that of a computer display, Inkscape can preview the printing output on screen by emulating the printer colors on your display. For this, you need to have two ICC color profiles: one for the printer you’re going to use and another for your screen.
Ideally, you should have your display calibrated using a special hardware device called colorimeter; this calibration creates a custom ICC profile of your display. If you cannot do calibration, a generic RGB profile, such as “Adobe RGB” from Adobe’s profile pack mentioned above, should work well enough unless your quality requirements are truly demanding.
In Inkscape Preferences, go to the Color management tab. Choose the display profile in the Display adjustment section. Then, in the Proofing section, check Simulate output on screen and choose the Device profile of your target device (i.e., printer).
For both screen and target device profiles, you can also choose Device rendering intent. The default Perceptual is the best choice in most cases; if you want the output to look as color-rich as possible (for example, when printing simple business graphics), try Saturation.
If a screen color is “out of gamut”—that is, cannot be rendered on the output device at all—it can be made immediately visible by converting it to a specially designated color. For example, if your design has no reds, check Mark out of gamut colors and choose red for Out of gamut warning color. Then, wherever you see red in your drawing, you know that you need to change the actual color of that object (it is of course shown correctly in the status bar or in the Fill and Stroke dialog, the red mark is only in the drawing) if you want it to print without gross distortions.
Screen proofing is helpful, but sometimes it is not enough—you may be required to produce a file already converted to the target color system. Such files are often called color-separated because they contain the separate color channels (usually CMYK, 8.2.2 CMYK) corresponding to the inks of the output device. Such a file may also have the target color profile embedded into it. The most commonly used formats are PDF (vector) and TIFF (bitmap); both can contain color-separated data and embed ICC profiles.
Although it can export PDF and render bitmaps, as of version 0.47 Inkscape cannot do color separation or profile embedding. You need some other software to do the job for you, such as Adobe Photoshop (for TIFF) or Illustrator (for PDF); both can import Inkscape’s SVG format directly. You can also use open source software; the Scribus page layout program (http://scribus.net) will import SVG and create color-separated PDFs, and the Separate+ plugin for GIMP (http://registry.gimp.org/node/471) will take Inkscape-exported PNG bitmap and convert it into a color-separated TIFF with screen proofing for complete control.