it"s not unusual for lobos ,acans or meat corals to morph in color.I would move it to more light but not to much at once.moveing a few inches to a brighter area will make a diffrence.If it shrinks up you are giving it to much. Mysis is good food for it but you might want to get some zoplankton.This could be dietary issue. I use to feed ours fauna marine lps food.Very good food.Good luck