Fish like the combo of grizzly and brown hackle. The body is gray just like lots of insects. Is it a mayfly? Is it a caddis? Is it a moth? Yes, it is a cross over pattern imitating many trout food items. I can always trick fish with an Adams. The parachute just makes it easier to see. The hi-vis option makes this fly even easier to see, especially on rivers that have lots of white foam on the surface.