4 or 5 different colors of food coloring, paste, or drops
Prepare the Royal Icing according to recipe directions and divide evenly among four or five small mixing bowls. Place 1 or 2 drops of each color into the individual bowls until the desired colors are achieved.
Place one color of icing into a piping bag fitted with a very small round tip (or you can use a plastic storage bag with just the tip of one corner cut off). Pipe a long skinny stream of icing onto a silicone mat or sheet of waxed paper. Repeat with all colors and let dry completely. Once dried, use a sharp knife to cut into small jimmies.