THE NUMBER OF DISCERNIBLE COLORS

How many colours can the eye distinguish? The published literature is remarkably inefficient at providing an answer to this important questi on. An often quoted reference states that ''10 million surface colours can be distinguished by the normal human eye under optimum observing conditions. '' Unfortunately, the authors fail to provide any further information as to thr origin of this figure, This short contribution d escribes some of the historical attempts at answering the question, an d then suggests a realistic solution. (C) 1998 John Wiley & Sons, Inc.