Optical Society of America (OSA) Uniform Color Scale Samples

In early 1977 the Optical Society of America (OSA) published a set of uniform color samples based on specifications developed by its Committee on Uniform Color Scales, of which the author is a member. The set consists of 558 samples; 424 samples represent a regular uniform sampling of the Committee’s color space; 134 additional samples halve the size of the differences between colors in the color space occupied by the near-neutral, central-lightness samples. The set is unique; it is designed so that each sample–except for a few limit colors–can be used in the formation of six uniformly spaced scales. The set provides scientists with visual proof of whether the Committee has reached its goal of specifying uniform color scales; it provides artists and designers with a tool with which they can lay out hundreds of perceptually equi-spaced scales, scales that can cut across color space in almost any direction desired, many of which have not heretofore been easy, or even possible, for them to produce.