Rulah and her "tribe" (including boy Nimbo) are white, while other "natives" are black. Umar is black but his evil "mate" Taho is a white member of Rulah's tribe: this interracial relationship is very rare in popular culture of the era.
Story begins on inside front cover.
Rulah and all of the enslaved women are white, yet the rest of the tribe, including one boy, are black, and the men even refer to the prisoners as "our women folk." No mention of this is made in the story and yet it is extremely rare in the pop culture of this era to openly suggest miscegenation. This is not a colouring error, since the women are all drawn with Caucasian features and the men are drawn with African features.
"Brainy Brats" is a spoof of the actual radio show "Quiz Kids."