Administration Guide : Setting global input ICC profiles : Overview

Ensuring color fidelity in printed images is a complex issue, as different prepress systems represent or encode color in different ways. Each device or software program involved in the many steps between the initial scanning of images and final output has the potential for influencing an image’s color representation.
The International Color Consortium (ICC) has published a set of specifications which, when adhered to, ensure that colors will be adjusted according to the characteristics of the devices used to process them. Part of the magic of ICC color fidelity depends on good ICC “profiles” which describe input and output devices. Each digital image can be encoded with a description of the color characteristics of its parent device. Before final output, a color correction engine maps these encoded characteristics to those shown in the ICC profile of the output device, making all necessary adjustments to ensure color fidelity.
A number of hardware manufacturers provide ICC profiles with their devices. You may also purchase libraries of profiles from third-party vendors. You will see reasonable results when you use these “generic” profiles; however, keep in mind that the profiles describe theoretical calibrated devices in factory-perfect condition and don’t describe the specific devices you have. For the best quality results, you should generate your own profiles for the input and output devices you use.
For more information about ICC color correction look at the International Color Consortium Web site, It includes several white papers on color management, as well as the full ICC profile specification.