About color management


    Because color-matching problems result from various devices and software using different color spaces, one solution is to have a system that interprets and translates color accurately between devices. A color management system (CMS) compares the color space in which a color was created to the color space in which the same color will be output, and makes the necessary adjustments to represent the color as consistently as possible among different devices.

    The following components are integral to a color-managed workflow:

    Device-independent color space

    To successfully compare different device gamuts and make adjustments, a color management system must use a reference color space--an objective way of defining color. Most CMSs use the internal CIE (Commission Internationale d'Eclairage) LAB color model, which exists independently of any device and is large enough to reproduce any color visible to the human eye. For this reason, CIE LAB is considered device-independent.

    Color management engine

    Different companies have developed various ways to manage color. To provide you with a choice, a color management system lets you choose a color management engine that represents the approach you want to use. Sometimes called the color management module (CMM), the color management engine is the part of the CMS that does the work of reading and translating colors between different color spaces.

    Color profiles

    The CMS translates colors with the help of color profiles. A profile is a mathematical description of a device's color space--that is, how the reference CIE values of each color in the color space map to the visual appearance produced by the device. For example, a scanner profile tells a CMS how your scanner "sees" colors so that an image from your scanner can be accurately translated into the CIE color space. From the CIE space, the colors can then be translated accurately again, via another profile, to the color space of an output device. Illustrator uses ICC profiles, a format defined by the International Color Consortium (ICC) as a cross-platform standard.

    Rendering intents

    No single color-translation method can manage color correctly for all types of graphics. For example, a color translation method that preserves correct relationships among colors in a wildlife photograph may alter the colors in a logo containing flat tints of color. Color management engines provide a choice of rendering intents, or translation methods, so that you can apply a method appropriate to a particular graphical element. For descriptions of the rendering intents available to Illustrator, see Specifying a rendering intent.

    Note: Don't confuse color management with color correction. A CMS won't correct an image that was saved with tonal or color balance problems. It provides an environment where you can evaluate images reliably in the context of your final output.