4-Stripe Damsel losing color?

[rwhite]

Just noticed our 4 stripe seems to be losing his "black" on his fins and the stripes are fading. Just did tests yesterday and all was in order and the other fish seem to be fine including a coral beauty and neon dotty, who I figured to be more sensitive. The only thing thats different in the tank is the addition of a BTA. Do you think this could be causing him stress? Or, hopefully, just a sign of age?

 

[rwhite]

okay, I was just feeding the BTA, Rics and Hairy shrooms pcs of fresh cut shrimp. Of course, everyone gets a pc or 2 during this process. But we noticed that the 4-Stripe has his color back. Is this an indication of under-feeding or something else?