vaginapagina | Random color changing vagina?

Soooo! I decided to have another looksy down at my vulva with a mirror because I had just shaved down there and I was wondering what was bothering me so much ( I must have nicked myself on my labia majora, didn't see a mark just redness)
Anyway while I was looking at that my attention was averted to my labia with has seemed to have gotten darker. Normally it was always pink, maybe a little redish but nothing this dark. Now it has all these brownish and purplelish undertones and I'm wondering, where the heck did that come from? What could cause the color to change like that? Could it be because it was already a little irritated because of shaving or what?
Has this ever happened to any of you? What were your experiences?

Backround info: Sexual active for over a year, about to come upon my period in a week or so, kinda PMSing right now, STD/STI free.

Thanks for any help!