Almost, if not all fish experience different colorations at some point in their life due to a lot of factors. I have South American cichlids, I've seen sick fish look pale meaning very bland coloring to washed out, excited fish with extremely bright colors, fish that breed usually have the best color and so on. I have a breeding pair of Fenestratus and Zonatus and they look like an almost different fish when they are breeding. Their colors change with their mood and many other factors.
