Maybe I am wrong. I am not trying to argue. Just participating in an interesting discussion:hello:
But I will say that I only keep anemones .... rarely fish or coral. I have purchased several white anemones in the 10+ years that I have been in this hobby. Everyone that survives, will regain color in my tank after 6 months at the latest. Of course the qualifier is that I only keep clown-hosting anemonies, I know nothing of other species.
When it comes to white vs. whitish there is a huge difference when it comes to anemones. White means no zooanthellae, and whitish/grey means zooanthellae.
I would love to see a picture of an anemone that has been under proper lighting in an aquarium for 6 months or greater that is pure white. I have NEVER seen it. Of course just becuase I haven't seen it, doesn't mean that it doesn't exist. i would love to see pictures, and to be enlightened.
I guess that you have seen many healthy white anemones. But I have bought many white anemones that have colored up or died, but never survived as white.