Help, question about my vagina?!?

Ok so, im a 15 year old girl and i had sex once, and my vagina lips are kind of a brownish purpleish color, is this normal? Im really self conscious and i do "play" with myself alot, like once or twice a day, and i was wondering if this could be the reason for the discoloration? Please help! and is there anything i can do to get rid of it? I read it has to do with age, but im only 15 so i dont think its because of that..