I have to agree with Carol... the term 'pastel motley' has been used to describe several varieties of cornsnake.
Some use it to describe Anery motleys. Some (like Don S.) use it to describe ghost motleys. Still others use it to describe pinkish ghost motleys only (though I've been told that only males ever show the pinkish coloration).
Your best bet is to ask the breeder what the genetic makeup of the snake is.
-Kat