SP, of course Rosa Parks stood up to them, but she didn't do it by crying 'racist' because she lived in an appallingly racist society so that would have got her precisely nowhere. She did it by standing her ground - or sitting her seat if you like - and by holding her head high and refusing to be less than the next person. Fortunately, you don't need to go to such lengths.
As Ludwig says, racists see the word 'black' as an insult, but if you don't then where is the insult? If people say you're black, then so be it - you are - so don't let the racist win by allowing what he perceives to be an insult to offend you. Racist words can only offend you if you allow them to. All the complaints in the world will never educate mindless morons, so best to treat them as the idiots they are. The word 'disdain' springs foremost to my mind - but of course, all of this is only my opinion.