Copperband Butterfly discoloration

[i3oosted]

Have a CB Butterfly that is eating plenty a few times a day, Mysis/Brine.

The problem is that his skin seems to be getting dirty, turning green/brown around the edges.

Could this be because I only have ambient light for the tank(FOWLR)? I just bought a reefbreeders LED light but won't be able to put it up until this weekend.

What could this be?

 

[i3oosted]

I may have jumped the gun, in the daytime his color is fine so it was probably his 'night' colors.

Any advice would be appreciated!