leucism is a over production of white. piedball are some sort of leucistic too. ivorys are leucistic ether.
in burms u got some leucistics with lonely single black scales.
most leucistics are not pure white. i would say the majority is dirty white (in all snakes).
its simple an overproduction of white- not a lack of ability to produce any color- therefore its comin that u have not true white sankes....