That show had some serious balls. There was the episode where Wheeler went back to his old neighborhood, and his dad was an abusive ass hat, while his mom was an ineffective victim.
There was the time they explained Ma-Ti's origin, and how his mom was a native Indian from Brazil, his dad was a white man, and the two sides were constantly trying to kill one another.
There was also the episode where a friend of theirs got shot at a high school, so the planeteers moved to the city, enrolled as students, pretended they didn't know each other, ended up in different cliques based on race, and joined different gangs to figure out who shot the guy.
I also remember an episode where they tried to stop two African tribes from killing each other, after Dr. Blight had given each side nuclear weapons. That same episode, Dr. Blight had given nukes to groups of Catholics and Protestants in Ireland, and the Planeteers tried to stop them too.