I found my book by Caucci and Nastasi on a rather scientific approach to color in fly tying. They explain how color is perceived, thus recreated. They discuss its importance in fly tying/fishing; and they offer a rather organized standard for producing various colors.
This is the outside slip cover of their book in the late 19780"s:
The book has about 13 color plate pages like this one. They are intended to represent "standard" a color selection guide for tiers. The idea was to produce a standardized method, through which, a tier or fisher could accurately communicate colors to another tier/fisher...........versus saying "Sort of a light olive" which is so different between the "eyes of the beholder".
If you look closely, there are "formulae" at the bottom of each color chip which then allow one to produce that particular color through another dubbing mixing chart provided.
The color plates provide about 1,200 specific colors with their make-up formula........
The formulae above are to be applied against this chart which shows how much dubbing of each primary color is to be used to produce the 3-color mixes required for any of the 1.200 color chips.
I may not have explained it quite accurately, so correct any errors I have made in my explanation.
Yes, it never became the accepted standard as intended as it seems no standard in fly tying is ever accepted.
It did offer an intriguing method of being able to create or recreate any of 1,200 specific colors by measuring the amount of 4 dubbing primary colors against the formulae provided.....................