What are you looking to find out? looks like just a white variety of the ocellaris. Care would be the same as all of the other designer clowns. Do they look more blue in person than they do in the pic?
unless you can see the parents, i wouldnt believe it. yes clowns can get some blue especially at the border between white and other colors but "blue ghost" just sounds like they are trying to sell wyoming whites at a higher price
The blue we sometimes think we see is simply where the black and white scales overlap. So technically, in order to have a completely blue clownfish, it would need to have rows of black and white scales overlapping perfectly, spread over the entire body.