Panda butterfly moor , a most fab fish
it's not just pandas that will loose there colour, it's all fish, if not cared for correctly due to stress e.g water quality, poor diet etc etc etc
If you care for your panda well like i'm sure u do all your other goldfish etc you should'nt have a problem! But and i hate to say it BUT now a days some or should i say most fancy goldfish are usaully colour fed in singapore/Hong kong where they usaully breed them to keep the colour which is a complete con so u might find that after a few months if it's not a very good strain or it has been colour fed it might turn completly white or completely black or even start turning orange/red
Hope this helps
