why is my chalice changing colors

[MohrReefs]

I'm just going to post a picture when I get home of the chalice and you let me know if you think its browning or not. It used to be flourescent yellow and now its dull. I had it directly under a redsea led90 about 2' down and the lights are at 75% blue 35% white. Also note that it no longer wants to eat.