Anemone was white... Now its brown?!?

There are currently 8 different clades of zoox that have been identified. There are over 800 subspecies that are currently identified included in those 8 clades.

Here's some good info.
Advanced Aquarist's Online Magazine - Feature Article: Lighting by Number: "Types" of Zooxanthellae and What They Tell Us

BTW, many bleaching events are on purpose hoping to obtain more light resistant or heat resistent zoox.