From the pictures I have seen I believe that the dots are a factor and that you are correct. One of the animals has a couple very tiny dots. I am thinking that the the white "blushing" that is normally seen on a spider might also be a factor. The father has a bit of the typical spider white. One of the babies seems to have less than the other two. From pictures I have seen of normal phantom spiders there seems to be very little white on the sides. I am expecting that this should remain true with the albinos as well.