Subtractive color or subtractive color mixing predicts the spectral power distribution of light after it passes through successive layers of partially absorbing media. This idealized model is the essential principle of how dyes and pigments are used in color printing and photography, where the perception of color is elicited after white light passes through microscopic "stacks" of partially absorbing media, allowing some wavelengths of light to reach the eye and not others. It is also a concept seen in painting, wherein the colors are mixed or applied in successive layers, though predicting realistic results (such as blue and yellow mixing to produce green instead of gray) requires more complex models such as Kubelka–Munk theory.