Well I personally have 3 (I know it should be 5+ but my tank is pushing it and I got these guys last in the tank) and 2 are very bright in color and one (the bigger one that I got like 2-3weeks before the other two) is kind of faded. I know he's getting enough to eat cause he seems to be top dog in basically the whole tank. I think its just genetics, and I absolutely love my "Mister Loach" (he's the faded one and you say it with a Spanish type accent.)