The only thing I can think of that it could be is that calico and champagne make for a white snake. I don't know this for sure but I can't find anything to prove otherwise and I was able to find one pic of a calico champagne and while it wasn't as white as yours, it does have a white appearance. It did not have cinnamon in the mix but like other white combos, other genes can be masked. So my guess is that your white snakes are calico champagne cinnamon.