Within the philosophy of color, there is a dispute between color realism, the view that colors are physical properties that objects possess, and color fictionalism, a species of error theory viewing colors according to which there are no such physical properties that objects possess.
Theories of color
One of the topics in the philosophy of color is the problem of the ontology of color. The questions comprising this field of research are, for example, what kind of properties colors are, but also problems about the representation of colors, and the relationship between the representation of colors and their ontological constitution. Within the ontology of color, there are various competing types of theories. One way of posing their relationship is in terms of whether they posit colors as sui generis properties. This divides color primitivism from color reductionism. A primitivism about color is any theory that explains colors as irreducible properties. A reductionism is the opposite view, that colors are identical to or reducible to other properties. Typically a reductionist view of color explains colors as an object's disposition to cause certain effects in perceivers or the very dispositional power itself. An example of a notable theorist that defends this kind of view is the philosopher Jonathan Cohen. Another type of reductionism is color physicalism. Physicalism is the view that colors are identical to certain physical properties of objects. Most commonly the relevant properties are taken to be reflectance properties of surfaces. Byrne, Hilbert and Kalderon defends versions of this view. They identify colors with reflectance types. A reflectance type is a set, or type, of reflectances, and a reflectance is a surface's disposition to reflect certain percentages of light specified for each wavelength within the visible spectrum. Both relationalism and physicalism of these kinds are so called realist theories, since apart from specifying what colors are, they maintain that colored things exist. Primitivism may be either realist or antirealist, since primitivism simply claims that colors aren't reducible to anything else. Some primitivists further accept that, though colors are primitive properties, no real or nomologically possible objects have them. Insofar as we visually represent things as colored - on this view - we are victims of color illusions. For this reason primitivism that denies that colors are ever instantiated is called an error theory.
Color discourse
If color fictionalism is true, and the world has no colors, should one just stop color discourse, and all the time wear clothes that clash with each other? Prescriptive color fictionalism would say no. In prescriptive color fictionalism, while color discourse is, strictly speaking, false, one should continue using it in everyday life as though color properties do exist. Color vision became an important part of contemporary analytic philosophy due to the claim by scientists like Leo Hurvich that the physical and neurological aspects of color vision had become completely understood by empirical psychologists in the 1980s. An important work on the subject was C. L. Hardin's 'Color for Philosophers,' which explained stunning empirical findings by empirical psychologists to the conclusion that colors cannot possibly be part of the physical world, but are instead purely mental features. David Hilbert and Alexander Byrne have devoted their careers to philosophical issues regarding color vision. Byrne and Hilbert have taken a minority position that colors are part of the physical world. Nigel J.T. Thomas provides a particularly clear presentation of the argument. The psychologist George Boeree, in the tradition of J. J. Gibson, specifically assigns color to light, and extends the idea of color realism to all sensory experience, an approach he refers to as "quality realism". Jonathan Cohen and Michael Tye have also written many essays on color vision. Cohen argues for the uncontroversial position of color relationalism with respect to semantics of color vision in Relationalist Manifesto. In The Red and the Real, Cohen argues for the position, with respect to color ontology that generalizes from his semantics to his metaphysics. Cohen's work marks the end of a vigorous debate on the topic of color that started with Hardin. Michael Tye argues, among other things, that there is only one correct way to see colors. Therefore, the colorblind and most mammals do not really have color vision because their vision differs from the vision of "normal" humans. Similarly, creatures with more advanced color vision, although better able to distinguish objects than people, are suffering from color illusions because their vision differs from humans. Tye advanced this particular position in an essay called True Blue. Paul Churchland has also commented extensively on the implication of color vision science on his version of reductive materialism. In the 1980s Paul Churchland's view located colors in the retina. But his more recent view locates color in spectral opponency cells deeper in the color information stream. Paul Churchland's view is similar to Byrne and Hilbert's view, but differs in that it emphasized the subjective nature of color vision and identifies subjective colors with coding vectors in neural networks. Many philosophers follow empirical psychologists in endorsing color irrealism, the view that colors are entirely mental constructs and not physical features of the world. Surprisingly, most philosophers who have extensively addressed the topic have attempted to defend color realism against the empirical psychologists who universally defend color antirealism. Jonathan Cohen has edited a collection of essays on the topic of color philosophy called Color Vision and Color Science, Color Ontology and Color Science.
