Most Helpful Girl
I know exactly how you feel; though I'm not blond, I've had to deal with the assumptions of negative black stereotypes for some time. It sucks because people pre-judge and don't see you for who you truly are.
There's honestly nothing you can do as far as changing your clothes; you could dye your hair another color, but I'm sure your proud of your blond color and want to keep it. ( Plus dye totally kills your hair.)
You just have to be you; those stereotypes will still haunt you every now and then, but when you start talking to people, and they get to know you, then they'll see they were completely wrong to begin with.
I always get the , " Your different than I thought, or you don't act like (stereotypical black people,)" once people get to know me. And don't psyche yourself out by thinking everyone thinks stereotypically of others, because there are a good number who don't.
Just be who you are and try not to reinforce any of the stereotypes. People who are honestly worth your friendship and companionship, will see you for who you really are, not what society has labled you to be :)