it could also be a dyed colt or another colt type coral that will loose it appealing color in time. for sure I dont know there are some different color combinations out there but very very FEW a true white most all of them are bleached from wrong lighting or a massive jump in lighting.
Latin Name Cladiella
Common Name Yellow Colt Coral
Also known as Yellow Colt Coral
Fast Facts The occasionally seen yellow Colt Corals are artificially died in Indonesia, where are collected. They dye eventually fades, but does not harm the coral. We do not stock these popular corals, nor are they regularly available, but if you want one, please contact us and we'll get one for you when available.
One of the best of all soft corals for the aquarium. Colt Corals are tan in color and have a highly branching form and are covered in small polyps. These corals grow quickly and can quickly become a showpiece. Does best in bright lighting and strong water movement, they can adapt to a wide variety of conditions. Larger specimens are more "branchy" than smaller ones and make an impressive display with pulsing water movement. Medium sized pieces are regularly available, larger and smaller pieces are less frequently available.
Note: These soft corals can expand and contract tremendously. Size will vary from smaller when you receive them, to larger until they have adjusted to your aquarium for a period of weeks
kenya tree coral
http://www.janetsreef.com/tree.htm I dont think its a kenya tree coral though
Mike