In large saucepan melt butter over low heat. Add marshmallows and stir until completely melted. Remove from heat. add in green food coloring until desired shade is reached.

Add crispy rice cereal. Stir until well coated. Add in 2 cups of cereal marshmallows and stir until incorporated into treats.

Using buttered spatula or wax paper evenly press mixture into 13 x 9 x 2-inch pan coated with cooking spray. Sprinkle with remaining cereal marshmallows. Drizzle melted white candy coating over top of treats and marshmallows. Allow to cool. Cut into 2-inch squares. Store in airtight container.