Cowfish color loss

[ReeferHD]

I’ve had my cowfish for about 6 - 7 months now but recently he has turned a very pale white and I dont know why.
He used to only turn white after lights out. He is still eating well. no trouble swimming in higher flow areas and no sign of sickness. He gets fed LRS reef frenzy, PE Mysis and nls pellets twice a day
First 2 pictures are what he used to look like.

 

[SPR1968]

I can’t answer the question, but I can bump the thread to see if we can get you some help