If the paint is dry (or wet) you can use hairspray to get most things out without using the decoloring of bleach and whatnot. Of course, if it's wet, you could just wipe it off with a moist towel.
Urine has certain chemicals that eat through paint but not leather. But it take quite a bit of it in order to effectively clean off all of the paint so you must gather your urine for about 2-3 days...