In small saucepan, combine frosting and candy coating; melt over low heat, stirring occasionally until smooth. Remove from heat. Stir in desired amount of food color.
Line cookie sheets with waxed paper. Using tongs, dip each cookie in melted frosting mixture, coating completely. Lay flat on paper-lined cookie sheets. Let stand about 10 minutes until set.
Decorate coated cookies with jack-o´-lantern faces using decorator icing. Top each with 1 gumdrop half for stem.