I think it may be a diet thing, but I have seen extremely yellow, almost chartreuse crappie in the delta also, as well as largemouth of all sizes that are very yellow.

That is the 17+ fly caught fish... I know of 1 other fly caught teener largemouth in the delta, and 2 or 3 others over 10, only 1 of them caught while actually targeting largemouth with the fly rod. My best fly caught largie is 8.5#, also striper fishing bycatch...so it doesn't count but a jumping and digging green bass on the fly rod with the line in both hands is fun anyway.

Marcus