Everyone has some sort of "hometown identity". Maybe you're known for what you wear, or for who you're friends with,or for something you did or said at one point.
You might be known for something that happened years ago, or even for something one of your friends said or did. Your identity might even be bigger than that -- you might be part of a sports team, or attend a high school with a strong sense of school spirit. However, your hometown isn't your entire identity. This doesn't mean that you have to dismiss everything from your past -- keep your varsity letters, your yearbooks, your pictures, and keep in contact with friends and acquaintances in from your hometown if you want to. There's nothing wrong with staying friends with your high school squad or flipping through your old yearbooks every once in a while. However, remember that there's a life after high school.
After you graduate, you're free to move on and change your identity, whether that be dying or cutting your hair, getting a piercing or tattoo, or even coming out. You can leave your high school persona and hometown identity behind, and explore new styles, ideas, and identities. Don't worry about what people will think -- do what feels right for you.
Maybe everyone in your hometown keeps their hair a natural color and you want to dye yours hot pink -- do it. Maybe everyone in your hometown are strong sports fans but you prefer the arts -- go to that museum. Maybe everyone in your hometown has a specific political view that you don't agree with -- support who you agree with. You're an individual -- you have your own opinions on politics, style, music, and your own identity. Don't feel like you have to follow along with everyone in your hometown.
It's okay to keep ties to your hometown if you want to. It's okay to dress the same way you did in high school, or to listen to the same music listened to in high school, or to keep your old yearbooks. But if you want to completely change who you are, go for it. Do what you feel comfortable with -- not what is the norm in your hometown, or what you think people expect you to do. Be true to yourself, and be happy with what you do. Your hometown doesn't have to be a major part of your identity unless you want it to be.