CMY Color Model

CRTs produce color by emission and uses the RGB model. Printers produce color by reflective light so it is a subtractive process and uses a model based on the colors: Cyan, Magenta, Yellow.

Remember that cyan = green + blue, so light reflected from a cyan pigment has no red component, i.e., the red is absorbed by cyan. Similarly magenta subtracts green and yellow subtracts blue. Printers usually use four colors: cyan, yellow, magenta and black. This is because cyan, yellow, and magenta together produce a dark gray rather than a true black.

The conversion between the RGB and CMY is easily computed as below:

C   1 - R
M = 1 - G
Y   1 - B

For example: C = 1 - R

R   1 - C
G = 1 - M
B   1 - Y

For example: R = 1 - C


Main Color page
HyperGraph Home page.

Last changed June 15, 1999, G. Scott Owen, owen@siggraph.org