These little guys are indestructible. They looked very drab and uninteresting in a shop tank, but given a few weeks to settle down they really brighten up. The photos here don't do them justice (not that I can do better). They need quite a few friends to give them someone to squabble with, but they're perfectly peaceful with all other tank residents. Attractive and easy to keep.
I love them, but they are not that pretty or long lived in a neutral-ish PH tank. They like acid and soft water - bordering on a blackwater tank, but not quite that extreme. They also like very clean water. They like a nice water flow as well. I'd go six minimum, but 12 is probably better as a few will die off initially. If you do all that and start feeding them live they take on IMO the best depth and complexity of color of any tetra.
I love this fish. from the time I was a beginner untill now, Ive always included them in my community tanks I usually keep 7 or 8 and they are happy peaceful and live a very long time excellant choice!