I'm not posting this under pet health, as I know sometimes it's normal for goldfish to change colour (ones I had a black one that turned orange, and that was "normal" I was told)....

But, Dr Evil, who's just had fin rot, but luckily seems fine now... has gotten a lot of black on him!!! Is this normal?
How Dr Evil used to look like...
What he looks like now...

Also, Big bugger Bubbah, who's still trying to get rid of his fin rot, has started turning black... I was wondering maybe it's a healing process?
What BBB used to look like...
What BBB looks like now...

Thanks for any input...!!!

Best wishes, Sylvie, KS' mom