comet color change

Question
I have a comet that has gradually changed from orange, to all silver/white.  Is this unusual?

Answer
Hi Ron,

It's not unusual for goldfish to change color. If this was a feeder goldfish once, then I would say it's definitely not unusual - these fish are incredibly inbred and crossbred because (theoretically) no one is buying them for their appearance! Black moors often change from all black to black with orange, it's one of the most common mutations. It's all genetics, doesn't really have much to do with its environment.

Just so you feel you are not alone, read this thread:
http://www.aquariacentral.com/forums/archive/index.php/t-29410.html

As you can see there was much debate about whether feeding or exposure to sunlight could reverse the effects. I really doubt the process can be stopped or reversed, but there are lots of reasons to offer your goldfish a healthy and varied diet, color changing aside:
http://www.kokosgoldfish.com/food.html
That link will give you all sorts of ideas for menus.

Hope that helps, take care!
Nicole