Remember that old ROYGBIV color wheel trick you learned back in grade school?
Well it turns out you're going to need it as an adult—but only to keep track of your eyeliner collection. Now you may be used to your tried-and-true black or brown pencil, but we're telling you: It's time to switch it up. Not only is swapping in a bright eyeliner a fresh and cool way to change up your look, it's also the easiest. That's especially true thanks to Marc Jacobs Beauty, which conveniently has a whole range of gel crayons in every color of the rainbow.