Yeah, bleached means the zooxanthellae (symbiotic algae that lives in the tissue of anemones, corals, etc.) has been expelled for one or more of the reasons mentioned. If you provide good water conditions and appropriate lighting, your BTA should soon re-establish the algae. The algae provides the bulk of the nutritional needs for anemones in nature. Until your anemone turns dark again, it would likely benefit from small pieces of shrimp, krill, mysis, squid, etc. Target feeding not only provides nutrition for the anemone, but also for the zooxanthellae and expedites the recolonization of the anemones tissue with these helpful algae. The anemone would likely benefit from small feedings (the size of a pea) 3 times a week until the anemone is colored up again.