My Goldfish Changed Colour To Blach

[stardoll786]

My fish is strange my common gold fish changed colour, I have 2 fish's both goldfish..i clean the tank every 5 days ..thy eat 2 kids of foods flakes and other..why is the bigger goldfish turnin black> is this disease or normal??

 

[AstonN24vantage]

what color was it before?

 

[Carlovel1]

Its normal in most cases. My old Goldfish was orange, then it started turning black