I am not the only one who thought Kim Possible's lipstick style was weird animation shadowing, or, a weird mustache. Seriously.
Naturally, I went looking for a tutorial and found this one that's pretty good! You can learn how to do all of her makeup or just stick to the lips (at 5:55!!)
Still, if I was going to cosplay anyone from Kim Possible, I think it's be Shego!! All that green XD