dark bubble coral

[robertmun]

I've had a bubble coral for about 4 months. It looks okay and expands really big, but I've noticed that the color of the 'bubbles' has darkened from a white to a pretty dirty tan color.

 

Is this an indication of some problem? My water is perfect, all other corals are fine, and I have no algae at all.

 

Like I said, it's nice and fluffy, just dark.

 

Thanks.

[Fishtails]

I'd think it has regained it zoolaxitane(sp.) and is now coloring up... What lighting is it under now and what was it under before?