We don't know about you, but we've found ourselves stuck in a lipstick rut more often than we'd like to admit. Sure, we love our tried-and-true favorites — variations of reds and pinks, and maybe a berry hue thrown into the mix — but every now and then, we find ourselves itching to try something new. And by new, we mean unexpected, unique, showstopping, and all-around cool. In short, rainbow lips.Experimenting with nontraditional shades like yellow, green, and blue can be extremely intimidating. But one look at Rihanna or Lupita Nyong'o wearing unconventional hues and looking exquisitely beautiful and badass, and you can't be blamed for your sudden desire to play with ROYGBIV lipstick. We asked professional makeup artist James Vincent and celebrity makeup artist Ermahn Ospina to give us their tips on how to wear every color of the rainbow. So whether you're looking for the best way to sport a silver pout or a few pointers on upgrading your go-to red lip, there are some tips in here for you.