This is the fourth paper in the category, 100 Papers You Should Read (in vision science).
William Rushton once said “The trouble with colour vision is the mentality of those that write on it-and of those that read. In most aspects of physiology it is sufficient to offer a fairly plausible and adequate hypothesis; but colour visionaries want nothing less than the truth. The cause of this unreasonable demand lies in this, that whereas nearly all the phenomena of nature are simply observed, those of sensory physiology can also be experienced. So in colour vision we perceive the essential hollowness of formal scientific explanation.”