That's odd. I keep a few different color strains spread amongst my three tanks and by the time they're big enough to see (about this size -> O ), I'm able to take a guess at what color they are.
I'd say give it another week or two. If you're purposely trying to raise them, maybe feed them a small piece of an algae wafer once or twice a week. Some liquid calcium (amount depends on tank size) or calcium rich vegetables couldn't hurt either.
Last edited by Raye; 07-22-2013 at 08:46 PM.