I use confetti rainbow sprinkles when I make this Lucky Charms bark recipe because I want to add a little bit of rainbow into the dessert. Plus, the confetti sprinkles are flat and round, so they lay easily and take up a lot of space in the gaps. If you prefer, there are round, gold sprinkles out there that feel like gold coins. Those would be cute too.  But really, the colors of sprinkles don't matter that much, so use whatever festive sprinkles you have at home. And, if you don't have any that really feel St. Patrick's Day-esque, just grab some leftover green sprinkles from Christmas. No one will know.