What would have made my black goldfish turn silver?

I got 2 black goldfish at the same time. I think they are Moors, but i'm not certain.


The point is that they were both black - Now the male one is still black and the female has started to lose its colour.


Is this common?|||Goldfish turn colour as they age, youngsters are black as they are not spotted by birds as easily and they turn orange or white when they mature, di|||i know that golfish change the couler of there scales as they age like everyone else has said my local vet has a beautifull goldfish tank and the vet said that the gold fish inb there all used to be orange then they turned white arter a while but of course its nothing to be conserd about u have a couler changing fish lol|||It is common for goldfish to change colors - though not all will. I had a beautiful red comet with a small white belly that now is a beautiful white fish.|||My black fish have often done that as they've aged. My guess is it's like how it is for people, you know getting gray hair and stuff.|||I know that orange ones turn white in the dark. Perhaps this is the same case for black ones.|||Maybe there's something in the water.