Pick up any textbook or article on vision from the current literature and chances are you will see the statement: "Human color vision is based on the existence of three types of cones, a red, a green, and a blue sensitive type", or very similar such wording. There is no discussion, no question, just this simple statement of "fact". With such an oft repeated and widely entrenched description of human color vision, there is surely no question that it is right. Or is there? This volume represents many years of effort on the part of the author as well as of a number of collaborators to try to better understand how human color vision works. Some of our work has been published in standard journals, but the key conclusions we have reached about color vision has run up against a very entrenched resistance and has not appeared in a unified form elsewhere.