Molting is just a fish like a rd/midas etc that goes through color changes. IE like some midas might be barred when small but will shed those colors to an orangy color. That's all I meant. Not a sickness, just a stage of growing for some.
The black on the tips of the tail and mouth is what I would think is molting unless there's another explaination. And the absense of a horizontal line leads me suspicious as well of this pic being a red dovii like claimed. But wanted to post it while we were on the topic.