It is even more complicated. I have a mojave x lesser that is a BEL. Looks just like a Super Lesser. Any combination of the animals I sent you makes BEL's. In order to understand all this you need to understand a little about genetics.
http://www.owalreptiles.com/geneticinfo.php
http://www.owalreptiles.com/complexes.php
Look at the BEL complex. Any combination of the animals there makes a "white" snake.
U really need to find out who made your snake and find out the genetics. That said, if you breed it to your normal piebald, you will find out what the genetics are because none of the babies will be white.
A lot of things with phantom tend to be a little more purple than white, but in my mind it is still a BEL.