Color of things important at many levels. When I try to catch larger groups of fish in spot here nets are not ideal in terms of shape or size, then I use two nets of differing color. One net is neutral / tone similar to back ground. The other is loud as in black or white. The loud bet is moved about and the fish retreat to the other net using it as cover.
A relatively new color change that is mood related for me pertains to how Bluegill color up to defend territories that have nothing to do with nesting.
A few years back I had four crystal clear ponds each stocked with 600 Bluegill representing Northern Bluegill, multiple stocks of Coppernose Bluegill, Hand-paint Bluegill, what I think were Southwest Bluegill, and all possibly crosses. It was like a trip to the candy store being able to see the color differences that could be discerned from 20 feet away with ease.
