orange/red digitata turned pink

I bought a orangish red digitata frag several months ago and it looked great
and grew fast for a long while. Over a month ago it started turning pink
and now it's very pink, I'm afraid to say almost white pink. I've been
reading about coral bleaching but nothing really matches my situation.
These have been pink for over a month, maybe even a couple of months. The
store I bought it from has his "parent" frags growing great.

Any idea why this happens and what I can do? It's getting plenty of light
from my halides and actinics.

Thanks for the advice.

B