I have a 3 inch frag of purple tip acropora sp.? that was given to me when I still had 130watts of pc. It grew...encrusting the base and growing about a 1/4 of an inch but it lost its color and turned a dull brown. Since updated to a 250watt de hqi xm20k the polyps which I didn't know where still there are coming back and I have noticed it turning lime green around the tips. I was wondering if it possible for a certain colored acro to completely change colors after it had gone severe changing in lighting. Thanks.