1) An ignorant racist, aka, a racist.
2) A racist so ignorant, they don't even bother to get their stereotypes right.
3) A person who is too ignorant to know that what they're saying is actually racist.
1) Mel Gibson.
2) Jeff: Jim just wished Hiro a Happy Chinese New Year.
Steve: What? Hiro's Japanese!
Jeff: What an ignoracist!
Steve: Haha, you should totally coin that word on UD.
Jeff: I can't, that Australian comedian Mikey Mileos beat me to it.
Steve: Man, he's awesome!
3) Jim-Bob: Man, I ain't seen yous guys in a coons age!
Billy-Joe: Two coons ages, I reckon!
**in the above case both Jim-Bob and Billy-Joe are ignoracists