Jim

Best suggestion I can give is that you check your local fly shop. He'll tell you the best color. Now when your on stream watch the fish. They'll root around to loosen the the scuds from the weeds then drop back to pick them out of the drift. when he drops back make your cast and lead it to him.
Color varies by stream in NJ where I'm originally from we used pinkfor scuds and shrimp on the Musky.

Tom