Space lattice used to sample the color space of the Committee on Uniform Color Scales of the Optical Society of America

The Uniform Color Scales collection provides twelve equally different colors around every color. Each is a member of six different scales, in which it is perceptually equally different from the two nearest neighbors. Those scales can be assembled into charts in which two (or three) sets of parallel scales intersect. There are three families of charts in which sets of parallel scales intersect at right angles. The scales on any one of those charts are entirely different from the scales on any of the other charts in the three families. In addition, there are four families of charts in each of which three sets of parallel scales intersect at 60°. In each of those charts, each color is surrounded by six colors that are perceptually equally different from it and from two of their fellows. Each chart of the seven families is analogous to a cleavage plane of a regular rhombohedral crystal, at the lattice points of which the colors are located.