Re: Why so many spinner colors?
This isn't exactly an answer to your question but the light in the morning and evenings at sunrise and sunset is redder than when the sun is overhead.
Gary Borger refers to a discussion he had with John Goddard of The Trout and The Fly, A New Approach, which has an extensive discussion on trout vision, pp 59 - 105. John had wondered why the Sherry Spinner which has a reddish orange tint would catch more fish than flies of the natural color. The puzzle was solved when John went under water and looked at the naturals which had a reddish glow due to the reddish light at sunset. The flat spinner wings on the water had an orange glow.
The red/orange light at sunset and dusk causes the naturals at this time of day to take on an orange reddish tint. Flies of this color fished at or near dusk will catch more fish than flies that are identical the color of the naturals. An orange spinner fished at sunset will "match the hatch" no matter what the color of the natural.
Matching the hatch is a concept based on selective feeding. Selectivity is a survival mechanism that trout have developed to gain the most food with the least effort because they feed efficiently and do not waste energy trying items that are "not food". They simply cannot help themselves.
To feed selectively, the trout have search criteria. You are familiar with size, shape, color and behavior in matching the hatch. These search criteria are called "triggers" that trigger the fish to feed.
Normally color is a minor search criteria, but when feeding on spinners with translucent wings, the sherry color of sunset causes the flat spinner wings to glow that distinct color.
The concept of accentuating a key feature of the natural that attracts the the fish's attention to the artificial vs the natural is called a "super trigger". The sherry spinner wings are a super trigger. It causes the artificial to stand out amongst the naturals and the fish seem to preferentially choose the artificial from amongst the naturals.
"Discovery consists of seeing what everybody has seen and thinking what nobody has thought"..........Szent-Gyorgy