Smallmouth Flies

Yellow over chartreuse Clouser, gray over white Clouser, Clouser crayfish, and his EZ popper in white. That is all I've ever used 95% of the time.
The bass like the Emerald Shiners so these green colored Clousers all make sense. I tie Wooly Buggers, sometimes with barbell eyes, and they are my all around streamer for bass and trout. I make some on big hooks and add a good bit of weight. The usual white black and olive colors work well.
Smallmouth are aggressive, given the right temps. They will give you a wide margin in fly selection. I fish a handful of flies because I know they work. I think the main things to consider are:
1. area of the water column (bottom, mid, top)
2. match the local bait (size, shape, color)
3. retrieve, depending on conditions.

You can shuffle the order of importance.

Color: How often have you heard "bass like white" or "It ain't no use if it ain't chartreuse", etc. While I like all white or a combo of white and chartreuse, I'm not sure it's very important. I'll bet an all purple marabou streamer that's 2-3" long with palmered marabou or schlappen would be great for smallies because it has the right size, profile, and movement (esp. when paused).
Years ago a Maine smallie guide had the advice you need only two colors - white (or something else light) for minnows and something natural (olive, brown, etc) for nymphs, crayfish etc. Have a minnow color and a crayfish color and you are good most of the time.
Kraft’s Kreelex, slumpbuster and stealth bombers are my go to’s.