Again, thanks for the comments. At this point I think I'll just recommend keeping it a Rainbow only pond without supplemental feeding and let the chips fall as they may.
In terms of fish flavor I have an interesting anecdote. Although I have never eaten pellet fed trout, I have eaten quite a bit of trout. I have another family member who lives on a small lake (really it's a very slow moving river) just below the dam that drains Tuloch lake in Jamestown, CA. This is the beginning of the Stanislaus River and one of the most beautiful places I've ever been. Anyways, when I fish there in the summer, the water is not flowing over the dam the trout are very difficult to catch. When you cut them open they are filled with snails and other bottom dwelling invertebrates. Unfortunately they taste like dirt...literally. However, in the winter and spring when the water is flowing over the dam, the fish are much easier to catch, much livelier, bigger (most in the 3-5 lb. range, some bigger), and when you cut them open they are filled with shad. These fish taste excellent, almost like crab. This experience tells me that there is some effect on flavor based on foraging.
I have the same experience, I'll ad a noticeable change in collor of the flesh do to the same reasons.
To compensate for the mud/dirt/soil taste I throw the trout in a box in a creek and let them starv for 5-7 days, before eating them.
The taste/flavor gets back to "normal" but it dosen't help on the collor.
As for farmd trout and salomon, I think they can be to fat in the flesh(over fed), and every so often have a odd/different odoor.