I remember some of the fuss over the "Color-C-Lector" device back in the 80's on the Great Lakes. If it said to use red, some joker would use green and catch as many fish as anyone.
I also remember reading the C/N book mentioned above and even as a kid thinking "yeah, let's STANDARDIZE a THOUSAND colors for flies.... right"
Anyone who has fished more than a few times has experienced instances when color seemed to be the absolute deciding factor, and other times when color made no difference at all. It is only one of a billion or so variables which are constantly changing, and one of the reasons fishing is so much fun. Attempts to put absolute values on those variables, and then use them to exactly quantify results, almost never work....
To the simpleton, proof does not matter once emotion takes hold of an issue.