Tape template to a baking sheet. Cut two 10-by-13-inch strips of freezer paper, and tape, shiny side down, to template.
Beat together sugar, meringue powder, and water with a mixer. Test it with a toothpick on a piece of freezer paper: Icing should form a domed dot that doesn't spread. If it forms a peak, it's too thick, so add a little more water, 1/2 teaspoon at a time. If it doesn't hold the dot shape, add a little more sugar, 1 teaspoon at a time.
Divide icing equally among 3 bowls. Mix 6 drops yellow food coloring into 1 bowl. Mix red and yellow to create orange in 2nd bowl. Leave icing white in 3rd bowl.
Transfer to 3 resealable plastic bags. Squeeze into corner, close off top tightly with rubber bands, and cut a small opening in a corner of each bag to create a piping bag.
Pipe dots onto templates, alternating colors, in any pattern desired.
Let stand, uncovered, until dots are firm and dry enough to be pulled off papers, about 2 days.
One box of confectioners' sugar yields enough white, yellow, and orange royal icing to make 10 strips of 60 dots.