Color variation in small fish is common on PC and I have n't come across anything definitive in the trout literature. My theory is substrate color under the fish may affect their color: dark bottom, dark fish; light bottom, lighter fish. I base this on fish from Grizzly Forebay and creek below the dam. In the Forebay and below the canyon section, the fish are typical colors. In the canyon the creek flows over a black basalt bottom. The fish here were almost black to below the midline. They were very well camouflaged. Lots of dark rock in PC

Sorry, the Angler Survey is temporarily down.  It had to be moved to a different server.

It will be working again very soon.

 

 

Thanks Keith. A friend at Cramer Fish Sciences once told me that it took trout only a few minutes to change their coloring to match their habitat. You can literally watch them do it.