Why is it racist?
Because his name is Keenan Thompson, He use to be on Keenan and Kel, and before that he was on All That, which is/was (i dont know if it's still on) a Nickelodeon version of SNL
When Will Ferrel hosted after leaving the show, they even did a joke in the opening monologue about what you just did. Will Ferrel couldn't tell the difference between Keenan and some other black guy that was on the show then, I think he was on the show just for 1 season or something. They had Ferrell's thoughts playing out loud, and in his head he kept trying to get the names correct, but he eventually called the one he was talking to the wrong name, hence saying that all blacks look alike.
And you just did all that again, but unintentionally, which I found hilarious