Ahh I didnt read the signature. 4.7 watts per gallon should be sufficient for a BTA. Hoops is right it is strange that you describe it as pink, green and red are normally the only two. If the anemone was in fact pink than it had already lost some of its zooxanthallae upon arrival in your aquarium, but to live for one year and start bleaching again is odd. My assumption is that if the anemone is eating, staying inflated and not shy about hosting the clowns its health may be fine.
I would consider PM'ing Fluff, she is an advisor here and helped me save a dying BTA that I had some time ago. She seems to be knowladgable with anemones and might have a better suggestion than I can offer. To me if your nitrates, nitrites and other criticial levels are in check than you should be ok. Do you feed it or add zooplankton of live brine to your tank for your other corals?