I have a weird smell coming from my vagina. I am a virgin so I know it's not a disease. But the seat in my underwear is like a brownish color is it a urinary tract infection or yeast infection?

Vaginitis. See a gynecologist for speculum vaginal exam and proper diagnosis. Just because you've never had intercourse doesn't mean you don't have an infection requiring treatment.
Could be yeast. A virgin can develop yeast infection of the vagina . See this site for information on this topic. http://women.webmd.com/tc/vaginal-yeast-infections-topic-overview.