Bubble Tip Coloration

[SiRhk]

Hey guys I have about 6-7 bubble tips, they are open and bubbly. One of them (my last one) was a rainbow bubble tip, she had at least 3-4 colors, now she has turned pink and green, lost the yellow orange tips.

My water is good, I don't have any problems with them closing up or shrinking just change of color.
I do run 2 gen3's and my tank is shallow I was wondering if this could be too much light?

I feed them every 2 days.