My girlfriend dyed her hair pink out of nowhere. I don't like it. What should I do?

She is a natural blonde. She said she was dying it a different shade of blonde (that's fine), but she sent me a picture last night and it's pink. I understand it's her hair and her choice. I like her for who she is, first of all. I'm not going to break up with her over it. This totally took me by surprise. I actually thought she was wearing a wig in the picture. I don't like unnatural colors in hair (she knows this form a conversation we had when we started dating), though I respect her decision. However as shallow this may be, I'm very uncomfortable about it. We haven't talked since the picture (I got it this morning and she never responded, nor to any of the three texts I've sent her). Like I said, I at first thought she was wearing a wig so my first text was "I like the wig :D". What can/should I do? A friend suggested I say something like, "the pink looks cute on you, but I think you look beautiful as a blonde", but after reading another post on this site I thought I'd ask for my specific situation. This is new to me. No girl I've ever dated dyed their hair unnatural colors, and I don't know what to do.
My girlfriend dyed her hair pink out of nowhere. I don't like it. What should I do?
Post Opinion