I can't say that I've ever had a fish "short strike" a spinner. I don't fish spoons much but I know that they both trigger the same kind of strike. A fish that hits a spoon or spinner most likely doesn't care about the insignificant flash given off by the hook, especially if you're using black hardware. As for stealth, in my opinion you can best acomplish this by downsizing. I own 2 colors of spinner in sizes 3 through 6. Gold and silver. 90% of the time I'm fishing a 5 or 6. unless the water is really low and clear, or there are other guys throwing hardware. At times I'll add color dots as Marty talked about to the inside of the blade. Most of the time though if I want more presence I'll tie on a bigger spinner. You should see the looks I get when I'm tossing a #6 spinner in Steelhead green water at medium flow.
I enjoy drift fishing and float fishing too, but if there is a fish present and a spinner or spoon is swung through its comfort zone correctly, that fish will hit 99% of the time regardless of time of day or water temp.
no better teacher than time on the water, and have confidence in what you're doing!
good luck