IMO all the suggestions are good. I have fished smallies for about 30 years and believe that while colour is important, especially so they can see the fly/lure for the light/water conditions, movement is the most important. My image when fishing for them is that I have to 'call' them, either with surface ripples or underwater flutters/wiggles. When fishing in lakes, casting and retrieving, there are times when I don't get many, but when I get the canoe underway (faster than I was retrieving) with strong paddle strokes, bang I get a fish. So I say use all the above with movement, sometimes faster than you would expect for trout or panfish.