I think it will be darn hard to Id that thing based on a picture, but it might be easier once it has grown. Easier just to go with colour/growth form to ID your coral then make an ID that might be wrong anyways. For example, I love my green table acro, but have no clue what species it is!
Also, check polyp expansion at night time with a flashlight. Expansion usually only occurs at night in the wild.
HTH.
