I currently have two 1.5-2 inch clown loaches in my 55 g tank, with one having particularly excellent coloration; very vibrant clear black and orange stripes. The other one, however, is not as attractive color-wise, he seems a bit washed out. I've seen other loaches with similar color problems, but those were all under adverse conditions (lack of food, space, oxygen, etc) and I'm not sure why one looks great while the other doesn't. Is there any specific food I can give to enhance his coloration, or anything else I can do in general? Thanks.