My best guess for which name Akro sold it under is Prizename. It _looks_ like it was meant to be a two-color marble -- blue and yellow. Yet I am counting four colors. It's just my hunch that Akro didn't mean for either the black or the white to be showing!
If they did mean for it to be a blue, white and yellow marble, for example, then I still wouldn't call it a Special.
I don't use the name "Special" to describe Akros. The marbles that most people call Specials were sold by Akro as Tricolor Agates.
(*waits for Chad to bonk me on the head with his rubber mallet*)
So maybe I would say "four color Akro cork" and not try to pin an Akro name on it.