On color (again)

The starting point of the argument is the observation that the appearance of qualities like color varies from observer to observer. The same object will look bright red or dull red depending on the lighting; a color blind person might not be able to tell it apart from a green object; another person’s color experiences could in theory be inverted relative to my own; and so on. The best explanation of these facts, the argument concludes, is that color is not really there in the objects themselves but only in the mind of the observer.

But there are several problems with this argument, which Putnam (1999, pp. 38-41) has usefully summarized (where Putnam is reiterating points that go back to writers like J.L. Austin (1962) and P.F. Strawson (1979)). First, the argument rests on a simplistic characterization of the commonsense understanding of color. Common sense allows that the same color can look different under different circumstances, just as it allows that a round object can appear oval under certain circumstances. Hence the commonsense thesis that color is mind-independent is not undermined by the fact that an object will look bright red in some contexts and dull red in others. Furthermore, color blindness no more casts down on the supposition that color is mind-independent than hallucination casts doubt on the reality of physical objects. In both cases, the defender of common sense can note that a perceiver’s faculties are simply malfunctioning, and thus not presenting objective reality as it really is. Meanwhile the inverted spectrum scenario presupposes that the physical facts about both external objects and the brain could be exactly as they are while the way colors look is different. It presupposes, in other words, that color can float entirely free of the way things really are in the material world. But that is exactly what the commonsense view denies, so that to appeal in this context to the alleged possibility of color inversion is to beg the question. (Edward Feser, Aristotle's Revenge, pp. 342-3)

The problem with Edward Feser here is privileging yellowish light from the Sun over all other lights. What happens if Earth orbits a blue giant start, or a red dwarf star?

Hence the reductionist would say that in a world without conscious observers, apples, oranges, and the like would not have color understood in the irreducibly qualitative commonsense way. This is so even though these objects would in that case still have the same surface reflectance properties they have in the actual world. But then, the reductionist himself is committed to the thesis that color, in the commonsense qualitative sense, is distinct from any physical property. Moreover, he is committed to the thesis that physical properties are neither necessary nor sufficient for color in that irreducibly qualitative sense – since, again, color in that sense would not exist in the absence of observers, even though the relevant physical properties would. (p. 346)

From a scientific viewpoint, color exists in the absence of observers.