Either a Tobiano or Overo Mutation. Could also be an Appaloosa Mutation.
Basically the Wing Shape of any Butterfly (and maybe Moth) in the Shoulder Area
Called Monarch or Lepidopterasis :3
Mo/Mo, Lep/Lep
I was thinking, with the "unnatural" colour filled in could be a Lep/Lep expression, a Lep/lep would only show the darker then base outline of the wings. I'll post a ref for the 2nd variation here.