Heat oven to 350°F.

Prepare cake batter as directed on package. Pour half the batter into separate bowl. Add 6 drops yellow food coloring and 3 drops red food coloring to half the batter; mix well. Stir 9 drops green food coloring into remaining batter.

Place 1 cookie in each of 24 paper-lined muffin cups. Spoon 1 heaping Tbsp. orange batter into each prepared cup. Repeat with green batter.

Bake 18 to 21 min. or until toothpick inserted in centers of cupcakes comes out clean. Cool in pans 10 min. Remove from pans to wire racks; cool completely.

Meanwhile, spoon half the frosting into bowl; spoon remaining frosting into separate bowl. Add 6 drops yellow food coloring and 3 drops red food coloring to half the frosting; mix well. Stir 9 drops green food coloring into remaining frosting. Spoon each colored frosting into separate disposable decorating bag. Cut tip off bottom of each bag. Place both bags in large resealable plastic bag, positioning tips in one bottom corner of bag.

Cut large piece off bottom corner of resealable bag where tips of filled decorating bags are; use to pipe both colored frostings onto tops of cupcakes as shown in photo.