West-coast steelheaders and salmon fishing have knows for decades that hair jigs worked through the water column (not jigged on bottom like for walleye), can get fish to strike when other baits and lures don’t.
Many Great Lake tributary anglers, especially in the bordering northern US states have also known for decades that fishing a small “jig-fly” either on it’s own or tipped with a small live grub like a wax-worm, or a few maggots can really produce when trout have stopped taking roe bags or imitation eggs.
I have had many days when the only way I could get both migratory browns and steelhead to take was to “shake” a small jig-fly under a float suspended off the bottom.
In turbid water dark colors have worked best like black and purple.
In clear water white and white-pink and white-green have worked extremely well.