I was re-watching this scene and noticed that Zebrowski's stripes looked spray painted (right) compared to Zebraxton's whose stripes are clearly defined (left). His ears and fur near his hooves are tan too and most of his arms are covered.

Looked up "are one of the Zebros a horse" and saw on the fan wiki page that he was. If it's true, I wonder if it's going to be revealed in the 3rd movie!