A very minor one in season 4: No matter how hard he tries, George Michael can't get a nickname that isn't associated with a celebrity who was caught in a sex scandal (specifically, George Michael, Boy George, and George Maharis, which was the name of an actor from the 1960s who was arrested for having sex with a hairdresser named Perfecto Telles in a men's room.)
Michael: How about Boy George?
News Anchor (in a flashback): Singer Boy George was arrested on charges of sexual assault today.
George Michael: I'll stick with George Michael. (quietly) At least it was consensual.
There are (very subtle) references all over the show to Tobias being a black man with a skin condition making him look white.
The black silhouette on the cover of "The Man Inside Me".
Tobias thinks Linsay's attraction to Ice might have something to with them having the same body-type.
Lindsay says that the name "Tobias" makes everyone think of a "big black guy", and Tobias answers that he is "not a big guy."
Lucille is shocked by a blue painted Tobias, and refers to the event as an assault by a "colored person".
Lindsay flirts with Herbert Love (Terry Crews) specifically because he reminds her of Tobias back when they first started dating.
His middle name is Onyango
You do occasionally see him wear something that looks like a dashiki
"Do you know China Garden?"
Over the course of season 4's last few episodes, Michael repeatedly suffers injuries to his left eye.