Maxwell, color vision, and the color triangle

Abstract

Even though James Clerk Maxwell (1831-1879) is justly famous for his pioneering work on electromagnetism, kinetic theory of gases and thermodynamics (amongst others) he also made fundamental contributions to our understanding of color and of color vision. In particular, he studied additive color mixing by use of the “color top”. From these experiments he determined color equations which quantified how much of each primary color was necessary to create any specific perceived color. He also devised ‘the color box’ to mix colors more precisely and performed psychophysical experiments. From these he went on to show that all colors can be represented in a two-dimensional space, a color triangle. This color triangle is a projection onto a two-dimensional plane, a three-dimensional color space. This research can be considered to be the basis of chromaticity diagrams which are widely used for defining color and color representation. Maxwell, studied color blindness using color matching experiments, with his color box. From these studies he concluded that color blindness was due to the absence of one of the three sets of receptors. He can rightly be called as one of the major contributors to color science and a co-developer of the “Young-Helmholtz” theory of color vision. These aspects are discussed in this paper.