I've got a fair mixture of tetra's in my 4' community tank, made up of the following:
Lemon Tetra's
Xray Tetra's
Rummynose Tetra's
Blue Tetra's (bought from Pier last Feb!)
The Lemon's are the most colourful of the lot, having coloured up nicely compared to when they were in the shop (very pale).
The Blue Tetra's are the most boistrus of the lot, and are always the first to feed, and shove everything else out of the way.... that was until I stuck the Geo's in there!
Been looking at topping up the shoal of Lemon's as I'm down to about 11, having started with 15 about 3 years ago. But at £2 ea at my local MA, I think I'll leave them for a bit.... unless I can get a deal at the weekend when I try getting an even better deal on the Farlowella's