My girlfriend told me she would potentially like to color her hair to something like pink or green. I feel really bad but I think I would find her less attractive if she were to do that.

I've always disliked really bright colored hair on people and for me personally, hair is a big part of attraction to a girl for me. I won't judge anyone for the color of their hair and I respect their choice but to me it doesn't look nice. 

Of course I acknowledge she can decide what she wants to do with her body and hair, I just don't know if I'll be able to appreciate it. I feel really bad for that.

I told her how I feel about it and she asked me if I would be less attracted to her, and I couldn't really deny or confirm. 