Coral Beauty lost color

[MPS]

I’ve got a Coral Beuty and a Flame Angel. They’ve been with me for 8mo +. I’ve had to put them in the Fuge for a month or so because I suspected they were nipping corals. Now, they are in a QT. They seem healthy except for the CB’s color. Is this a symptom of something beyond nutrition? Durin there isolation, they were fed the same as while in the DT; Ocean Nutrition pellets. They also fed on sponges and adult copapods.
Ideas on why my CB has lost most of its color? What steps can I do bring this one back to full glory?

 

[EmdeReef]

Is it a young angel? Any aggression between the two? Malnourishment, stress or Bacterial issues can cause this.

Any medications in the QT?

 

[MPS]

There have been past aggression issues but those stopped once they were banished to the sump. Now in QT, they get along great. Yes this is a young Angel but it used to have much better color. Here us a photo from 3 months before. I'll try to boost his nutrition intake. I can soak the pellets in Selcom and up the mysis shimp.
Hopefully I can turn this one around. Thanks for the feedback.

 

[DSC reef]

I would try to feed a wide variety of foods. Typically 2 dwarf angel fish in close quarters can be a problem.

 

[Jesterrace]

Yup, LRS Reef Frenzy should give it a buffet diet in a single food source.