excerpt from http://lexar.com/dp/tips_lessons/nottaken.html
Color Profile - The camera color profile specifies the relationships between all of the colors so that once the correct white balance is achieved, all of the other colors [under the same illuminant] will be rendered accurately. Accurately rendering all colors in the rainbow is as important as achieving the right white balance. Color profiles can be specific to a software or even custom-made to your own specific camera body to account for sample-to-sample variations. To the extreme, lens-specific color profiles can be developed to account for the tonal signature of each lens design.