Excerpt: Even more rarely, coloration may be possible to use in distinguishing genera (e.g. Halomitra sp.v. Sandalolitha spp., various Tubastraea spp., and others). I emphasize that there is no case of which I am aware where coloration will be a criteria in taxonomical determination, but may provide clues to separate similar groups or species.
thanks i have the book aquarium corals by Eric Borneman from what he says i im leaning towards halomitra which he if the top side of the septas are smooth its halomitra is that why you probably need the skeletal structure