CMYKColor[cyan, magenta, yellow, black] is a graphics directive which specifies that graphical objects which follow are to be displayed in the color given.
Color levels outside the range 0 to 1 will be clipped.
CMYKColor can be used to specify colors for color printing.
CMYKColor specifications are automatically converted to RGBColor when simulated lighting calculations are done.
See The Mathematica Book: Section 2.9.17.
See also: RGBColor, ColorOutput.
Related package: Graphics`Colors`.