1. With an electric mixer, mix sugar, meringue powder and 1/2 cup water on low speed, scraping sides of bowl until icing thickens to a yogurt-like consistency, about 4 min.
2. Divide icing among three bowls and tint black, green and orange. Transfer to piping bags fitted with #3 plain tips and secure bag ends with rubber bands to prevent drying
3. Create a smooth layer of icing by outlining each cookie first; then pipe in the center area (icing will run together). Let dry about 10 min before adding spirals. Allow icing to set about 3 hr or overnight. Store covered for up to 1 week or frozen for up to 2 months. Makes 4 dozen frosted cookies.