Are their any health benefits to wearing white briefs for underwear?

Color doesn't matter: The color of the briefs doesn't matter. It's just fashion. However, having white laundry means one can add bleach to the laundry. That helps keep one's washing machine clean and fresh-smelling. Thus, it's beneficial to run one load of laundry with bleach, once a week. For guys, wearing briefs instead of boxers, or instead of nothing, helps prevent the testicles from flopping around during sports.