Who's the Asian kid in this picture? The first kid is the girl from "A Noun is a Person, Place or Thing." The second kid is the mysterious boy of Asian descent. The third kid is Schoolhouse Rocky in his "normal" form (akin to Billy Batson and Captain Marvel). The fourth kid is the girl from "Body Machine." Given that all of the kids are from the original run of videos in the late 70s, shouldn't the Asian boy be from a video too?
Considering the other kids appear in Grammar, Mathematics, and Science Rock songs; he probably appears briefly in America Rock.
Trust me; he never appears in a single SHR short. Besides, Schoolhouse Rocky represents the entire series, not Mathematics Rock.
Maybe the colorist didn't know who Chubby Checker was, or wasn't informed it was Chubby Checker (he wasn't exactly well-drawn).
Word of God is that it was a simple colouring error on the part of the animation team, which, yes, was probably helped along by the complete generic-ness of the drawing — nothing about his appearance indicates that he's African-American.