You need to upgrade your lighting if you hope to successfully keep the anenome. Anenomes require strong lighting - at least 3 to 4 watts per gallon. The white color of your sebae's tentacles is not its natural color - it's natural color is more of a brownish color. It has that white color because it has lost its zooxanthellae. I agree with Marco333, they need to be target fed (mine seems to really like squid and krill) - just drop a piece of food on its tentacles and you should see it respond.
I am certainly not an expert on anenomes - I'm just passing on the information that I've read and gathered.
I know its frustrating when you get conflicting advice. This board though is a GREAT resouce - the people here are passionate about this hobby and want to share their experiences and knowledge for free - many (not all) LFS just want your $$$.
Also, in trying to make a joke, I said something incorrect - it's not their bottom but technically their "foot" that you're always seeing - since they expel their wastes through their mouths.
Miles