Hello, and welcome to the site!
Anemones are a pain in the butt, I have renamed them beautiful fish eaters. Cover your power heads, because they will follow the water flow and commit sushi, poisoning everything in the tank as it dies.
They need lots of light, the most powerful... such as Metal Halides or the new LED types. Fluorescent lights are no where near powerful enough, ever. If you have enough T5HO bulbs it's a big maybe. I'm talking sun shine in a box power.
The next thing that's very important are the water parameters. Anemones need near perfect conditions, so we don't get one until the tank is at least 6 months mature. A new tank goes through all kinds of adjustments and stages the first year it is set up, an anemone needs very stable conditions.
Your anemone turned grey color because it is super stressed out. The list that tthemadd1 asked is right on spot, all those questions need to be answered for us to really be able to help you..