Billmeyer and Saltzman's Principles of Color Technology, 4th Edition

Chapter 8Metamerism and Color Inconstancy

We hope our readers recognize that the single most important aspect of color vision, particularly from the standpoint of color technology, is metamerism. Because of the trichromatic nature of our color vision, spectrally dissimilar stimuli can produce the same visual response. As a consequence, it is possible to produce color matches without using the identical materials. Metamerism has enabled many different color technologies to flourish. Most color reproduction systems including television, photography, movies, and printing rely on three or four primaries to represent our chromatic world. Colorants found to be toxic can be replaced with more benign ones. Colorants can also be replaced in order to reduce cost. Because of metamerism, it is possible to reformulate a color recipe using different colorants. Designers can coordinate the colored items in a room to match one another despite being made using dissimilar colorants. For these examples, metamerism is a blessing. It is also a curse because these matches are often conditional, matching for only one observer, and if the metamers are samples, for only one light source. When the change in lighting leads to a large color mismatch, one of the samples changes color dramatically, that is, it exhibits color inconstancy. If either sample can be the standard, the most color constant is a better choice.

A. METAMERISM TERMINOLOGY

In Chapter 2, we define metamerism as the phenomenon in which ...