I seem to have a color mutation in one of my Denisons. His color and pattern keeps changing. It was mostly yellow (full grown) with a very large orange stripe and yellow/black stripes on his tail fins. then he started getting some black splotches, returned to the mostly yellow, then almost into a standard pattern, and now its losing the black stripe on the side and getting splotchy black on his back. This happens gradually over time, but it progesses noticeably on a day to day basis. As far as I can tell, its healthy, his tank mates accept him and he acts the same as the other Denison in my tank. Anyone else seen this type of color mutation?