Tired of being called stupid by my friends

I just really need to get something off my chest, and I'm hoping someone could give some advice or input. I'm the "dumb blonde" of my friend group. I'm not even blonde, but somehow I've been stereotyped into this role and I've had enough of it. You see, beyond this friend group, I have a life that's pretty different. I'm proud of my accomplishments, and I know they demonstrate that I am anything but "dumb." However, when I'm with that friend group, it's like I'm a completely different person. They always make jokes, imply I'm dumb, and it's become more than just playful teasing. At first, I laughed it off, thinking it was all in good fun. But now, it's started to really bother me. It's like they've forgotten who I am outside of the group. And the dumbest part is that around them, I really started stuttering when I talk and saying stupid things. And when that happens they certainly don't leave it unnoticed. It's hurtful and it's undermining my confidence. It's reached a point where I dread hanging out with them because I know the "dumb blonde" jokes are just around the corner.

So here's where I need your advice. How do I make them understand that their comments are hurtful without sounding overly sensitive? I'm also wondering if anyone else has been through something similar. If so, how did you guys handle it? I’d really appreciate any advice or insight you all might have.

Thanks for listening.