Additive color
Additive color or additive mixing is a property of a color model. It predicts the appearance of colors made by happening together part lights, i.e. the perceived color can be predicted by summing the number-based representations of the part-related colors. Modern recipes of Grassmann's laws describe the additivity in the color perception of light mixtures in terms of algebraic equations. Additive color predicts perception and not any sort of change in the photons of light themselves. These predictions are only related in the limited scope of color matching experiments where viewers match small patches of uniform color isolated against a grey or black background.