risky to buy any stessed coral at the LFS. There is no way of knowing what caused the bleach or for how long it has been that way. While in this state corals do not photosynthesis well because of the lack of zoaxanthellae. It could be on its last ends with all of its energy reserves used up all ready. But since brains are such good eaters you may be able to feed it up, say like 3x a week till it regains its color????????? Bleaching is an all to common occurence but can be overcome. If you do buy it put it under an overhang in very low light at first and slowly acclimate it back to light.