MFC Galloup's Dungeon - Natural

What a big brown actually eats: a smaller trout

The biggest fish in most rivers are not eating insects, they are eating the fish below them in the pecking order, and the natural dressing puts that in front of them without any pretence. A mottled brown back over a pale belly is what a juvenile trout or a galaxias looks like from underneath. It is the version to use in clear water, where a black fly can be too stark and a bright one simply clears the pool. Same aggressive retrieve, just a more plausible fly on the end of it.