Editing Color (section)

=== Development of theories of color vision<span class="anchor" id="Development of theories of colour vision"></span> ===
{{main|Color theory}}
[[File:Optical grey squares orange brown.svg|right|thumb|250px|The upper disk and the lower disk have exactly the same objective color, and are in identical gray surroundings; based on context differences, humans perceive the squares as having different reflectances, and may interpret the colors as different color categories; see [[checker shadow illusion]]]]
Although [[Aristotle]] and other ancient scientists had already written on the nature of light and [[color vision]], it was not until [[Isaac Newton|Newton]] that light was identified as the source of the color sensation. In 1810, [[Goethe]] published his comprehensive ''[[Theory of Colors]]'' in which he provided a rational description of color experience, which 'tells us how it originates, not what it is'. (Schopenhauer)

In 1801 [[Thomas Young (scientist)|Thomas Young]] proposed his [[trichromacy|trichromatic theory]], based on the observation that any color could be matched with a combination of three lights. This theory was later refined by [[James Clerk Maxwell]] and [[Hermann von Helmholtz]]. As Helmholtz puts it, "the principles of Newton's law of mixture were experimentally confirmed by Maxwell in 1856. Young's theory of color sensations, like so much else that this marvelous investigator achieved in advance of his time, remained unnoticed until Maxwell directed attention to it."<ref>Hermann von Helmholtz, ''Physiological Optics: The Sensations of Vision'', 1866, as translated in ''Sources of Color Science'', David L. MacAdam, ed., Cambridge: [[MIT Press]], 1970.</ref>

At the same time as Helmholtz, [[Ewald Hering]] developed the [[opponent process]] theory of color, noting that [[color blindness]] and afterimages typically come in opponent pairs (red-green, blue-orange, yellow-violet, and black-white). Ultimately these two theories were synthesized in 1957 by Hurvich and Jameson, who showed that retinal processing corresponds to the trichromatic theory, while processing at the level of the [[lateral geniculate nucleus]] corresponds to the opponent theory.<ref>Palmer, S.E. (1999). ''Vision Science: Photons to Phenomenology'', Cambridge, MA: MIT Press. {{ISBN|0262161834}}.</ref>

In 1931, an international group of experts known as the ''Commission internationale de l'éclairage'' ([[International Commission on Illumination|CIE]]) developed a mathematical color model, which mapped out the space of observable colors and assigned a set of three numbers to each.