The study of the perception of color is historically intertwined with the study of the physical nature of light. The early discoveries in optics were made on the basis of direct observation, confounding the effects of perception with the physical nature of light. In the case of color, this led to a series of confusions which lasted for nearly two centuries.
Newton noted that light passing through a prism was affected such that different colors of light were refracted at different angles. He made careful measurements of these spectra, recombining them to recreate white light and concluded that ``Light it self is a Heterogeneous mixture of differently refrangible Rays''. He also made the observation that an object which appears red in sunlight could be made to appear any color by illuminating it with pure spectral colored light, but that it would appear brightest when illuminated with red light. From this he concluded that the appearance of color is due to differential reflective properties of substances.
Newton also suggested that the perception of color was due to some differential impact of something like the frequency of light upon the eye.
Now the most free and natural application of this Hypothesis to the solution of phenomena I take to be this: That the agitated parts of bodies, according to their several sizes, figures, and motions do excite Vibrations in the aether of various depths of bignesses, which being promiscuously propagated through that Medium to our Eyes, effect in us a Sensation of Light of White colour; but if by any means those of unequal bignesses be separated from one another, the largest beget a Sensation of a Red colour, the least or shortest, of a deep Violet, and the intermediat ones, of intermediat colours; much after the manner that bodies, according to their several sizes, shapes, and motions, excite vibrations in the Air of various bignesses, which according to those bignesses, make several Tones in Sound. [Newton 1672a]
While most of Newton's observations had to do with spectral light, he observed that by mixing yellow powder and blue powder together one obtained an apparently green powder. However, by looking at the apparently green powder under a microscope, one could determine that the powder was still comprised of blue and yellow grains. He thus confused additive and subtractive colors, a confusion which persisted until the time of Maxwell and Helmholtz.
Figure 1. Newton's color wheel (from Newton 1704; Book I, Part II, Plate III).
Newton should be credited with the first model of perceptual color space, essentially a color wheel with white in the center (see Figure 1). This type of two dimensional slice through a color opponent space has persisted in most formulations of perceptual color representation to this day.