I do NOT know what name Akro had for this marble. Is the ribbon white -- did all the yellow appearance come being immersed in the baseglass? Or is the ribbon yellow? If white, then okay, easy vote for "sweet sweet onyx". But if it's yellow, then I don't know which if any of their library of marble style names Akro was formally presenting this under. At that point, I'm saying "Collectors, let your imaginations roll."
Edit: or maybe I wait and hope that someone does know what box it came in .... Maybe Art's box pic suggests that Akro WAS trying to slide a champagne-based marble into their white-based Ace inventory as they sent the salesmen around to show off their wares. Would be interesting if we had more boxes to show that happening.
But if it does turn out that the ribbon is white, then back to easy onyx.