When Akro made it, they called it a Moss Agate.
Collectors have been known to call it an Ace.* I can't remember ever hearing of a "Sunset Ace". But it's a kinda cool name actually and I wouldn't be surprised to hear someone else say "Of course!". lol
*The marble that Akro called an Ace was a completely different type, but a great number of Akros still call these mossy marbles Aces.