Those are some sweet looking fish. It will be interesting to see if they can stand out in planted tanks with lush, green plants.
I have a school of them in my 20L--they're very active and generally a lot of fun to watch (more so then chili rasboras for example) but it seems like their colour is much more reflective then passive. Under my lights (spiral CFLs) they look quite boring when backlit but stunning when on towards the back of the tank and the light is reflecting off the silver-green scales. I was really disappointed at first, but adjusting my water flow so that they hang out towards the back of the tank has completely sold me on them. They like high-flow areas and it was fairly easy to move them around by aiming a powerhead where I wanted them to go.