Not matching the Hatch....
When early season fish are midging--when there are zillions of itty-bitty bugs on the water and when fish are dimpling every where you look--brighter than natural seems to be what gets noticed most.
The same thing happens in May, during Montana's Mother's Day Caddis hatch. When the surface of the water is obscured by billions of seething caddis, and when the fish are dimpling where ever you look, abnormally bright flies seem to attract the most attention. Size matters (a lot). And color too. But maybe not in the match-the-hatch way most people think.
Do these hot colored flies really work better? Maybe it's too soon to make a claim that radical. But I can tell you I've been fishing them all Spring this year. And at the very least, they work just as well (as a more subdued and naturally colored fly).
Attractors are supposed to be what works in between hatches. These seem to work just fine, right in the middle of a hatch. If you go too large you don't catch fish. So maybe size matters most of all. And Twinkly-bright can (at least sometimes) be an added bonus. Hot little wets seem to work well during the BWO hatches too, which are just now about to get going (here in SW Montana).