Bleaching GTBA - What to do?

[hillegom]

I bought one that was completly bleached. Pure white. Feed him once a week or so, not very much, and now months later it is brown. But my lights are not very good.
compart flourescents. I try to feed raw seafood. and pe mysis. When we eat fish/prawns/ whatever, I save some and freeze it before cooking.
I have not had mine too long so hopefully, someone with more experience can chime in