I have a group of 6 rosy barbs. 2f, 4m. When I bought (in October) them the males were all neon bright.... Over the past few months they have been getting duller and duller.. except one, who is light a glow light! It has been happening very gradually, but i was looking at old pics the other day and thought, wow!! Are those really my fish! The difference is astounding. There is one other who is slightly "rosy" but the others are so dull now I really have to look close to work out which are girls and which are boys. I am guessing it may be an alpha thing? The most dominant fish becomes the brightest? Is there anything i can do to help improve it? I have tried conditioning them with lots of frozen food in addition to their NLS thera A... but it hasn't made a difference. Water paramaters are 0,0, 20ish. 1/3 water change is done weekly. The only issue maybe that they do nip each other quite a bit. Most of them are long finned. The two girls' fins are fine (both LF) but the boys regularly have tears. They don't bother the other fish that live with them (mr+mrs Krib and cardinals, BN pleco). And nothing else seems to bother them. Any ideas?