RGB4

In the additive model, if the resulting spectrum, e.g. of superposing three colors, is flat, white color is perceived by the human eye upon direct incidence on the retina. This is in stark contrast to the subtractive model, where the perceived resulting spectrum is what reflecting surfaces, such as dyed surfaces, emit. A dye filters out all colors but its own; two blended dyes filter out all colors but the common color component between them, e.g. green as the common component between yellow and cyan, red as the common component between magenta and yellow, and blue-violet as the common component between magenta and cyan. There is no common color component among magenta, cyan and yellow, thus rendering a spectrum of zero intensity: black.