The skin of my vagina has gone from pink to white. Not discharge. The skin is turning white. Is this a STD if so which ones can cause this.?

See your Gyn. It would be helpful to know your age. Any area on the vagina or vulva that turns white needs to be biopsied because in some cases this is a pre-cancer. There are also b-9 causes such as vitaligo, Human Papiloma Virus, warts, to name a few. This is a situation where you need to see your Gyn for an evaluation to know for sure what it is and make sure its not serious. Best wishes!