My hair colour is ruining me

I feel so angry and depressed. It has only been two weeks since the start of term 4 begun, and I'm already being targeted. Again. After my topic "Why won't they stop?" I felt like I was in control of the bullying. Things settled down for a while. Until I earned myself the nickname match-stick. A boy who is friends of a group who used to bully me is now having a go at me whenever he can because I have white skin and bright red hair (red dye).

It started out okay at first. I was sitting at my usual spot with my friends when a girl who has a very dirty mouth (I talk to her because she has no friends and is always on her own at lunch) came over to my group and sat down next to me. My friends hate her and they kept glaring at me accusingly, like I had brought the girl here. Anyway, she told me that this boy (I mentioned him earlier) was calling me match-stick every time he sees me. He says "Ooh, look! There's matchstick! I'm going to drag her across the ground until she lights up!" The girl asked me if I wanted her to go and say something mean to him. I said she could but I laughed and told her that I was joking. I went back to reading my book. Soon after, the girl came back giggling. She told me that she had gone up to the boy and called him a "black bitch" and she said that I said that he was. (He has dark skin). I was horrified. I will never call someone that even if I hate them so much, because I am totally against racism. I was furious at the girl. About less than a minute later, the boy and a large group of his friends (thugs) came over and stood in front of me and called me matchstick and they gave me death threats and they all said stuff like "quick! grab her and drag her across the fucken concrete". I ignored them and kept reading my book. Eventually they became bored and went of to start a fight somewhere else. My best friends didn't even stick up for me. One of them was sitting right next to me, and she claims that she has no idea that I am being bullied. This has happened 4 times now and I am pissed off. For some stupid reason I burst into tears last night and told my parents everything that happened. On Tuesday, the principles are going to talk to me about it. I want to dye my hair back to plain brown but my parents think that I shouldn't. Now everyone calls me match stick as I walk past. My hair has caused me nothing but trouble, how can I change what happens to me?