I didn't see a goldfish section on here, but I have a bubble eye goldfish, named Chuckie, who is turning black. He was completely orange in color and now the pigment has started to turn, and he's about 1/2 black 1/2 orange. He's always been a weird fish, sits on the bottom and chills, but he's been "chilling" a lot more lately. Any ideas of whats happening with him? Water is fine, everyone else is fine, and he doesn't have any marks, blemishes or anything else.