# Color Conversion

### To convert from one color gamut to another is a simple procedure.
Each phosphour color can be represented by a combination of the CIE XYZ primaries,
yielding the following transformation from RGB to CIE XYZ:

### The transformation
yields the color on monitor 2 which is equivalent to a given color on monitor
1. Conversion to-and-from printer gamuts is difficult. A first approximation
is as follows:

` C = 1 - R`

M = 1 - G

Y = 1 - B

### The fourth color, K, can be used to replace equal amounts
of CMY:

`K = min(C,M,Y) C' = C - K`

M' = M - K

Y' = Y - K