I do not believe it is breeding color, as they have bred three times now. The last batch of fry hatched two weeks ago. At that time he was much darker and blue (second from last pic of the male). Only in the past few days has the black shown up and the gold shown up. It began with parts of all of his fins changing to a gold color. Then a few gold streaks showed up in the face. Regardless, I can't decide which color pattern I like better. I am also not convinced that this change has been completed. I can't wait to see where it goes from here.