Over a wide range of conditions of observation, many colors can be matched completely by additive mixtures in suitable amounts of three fixed primary colors. The choice of three primary colors, though very wide, is not entirely arbitrary. Any set that is such that none of the primaries can be matched by a mixture of the other two can be used. It follows that the primary color vectors so defined are linearly independent.

Therefore, transformations of a metameric match from one color space to another can be predicted via a matrix calculation. The limitations of color gamut apply to each space. The additive color generalization forms the basis of most image capture, and of most self-luminous displays (i.e., CRTs, etc.).