Nonpareils are the teeny sugar balls used to decorate cookies. Here are some pictures of rainbow nonpareils (you can find small jars or tubs of them in the baking aisle of the supermarket).
To get them to adhere to a cookie, make an icing of confectioners sugar and water, spread it on the fully cooled cookie and add the nonpareils. Leave the cookies out so the icing can dry. The nonpareils will stay put!
Name the Cookie