With the exception of rainbow shiners, all the hydrophlox shiners I've ever seen are grey with a black stripe down the side most of the time in the wild. Rainbows are grey, with a black stripe down the side and a red stripe above the black.

I've never personally seen them in technicolor except in photos, but I agree they're stunning when they are. In captivity, in my experience, they exhibit more color than in the wild (better temps and food, I'd guess) but not the super bright colors all the time. They're still quite good looking, hardy, fun fish with a lot of activity and practically zero time acclimitizing them to tank life.

(Mr. Wolfe knows more about keeping them than I do, and I can personally vouch for the fact that those under his care look better than mine. I still think they're just about the most perfect tank fish in north america. I just like sunfish better. ;P)