In a large pan, melt butter over low heat. Add marshmallows and stir until completely melted. Remove from heat. Tint with orange food coloring. Add rice krispies, stir until well coated. Using greased 1/2 C. measuring cup, divide warm ceresl mixture into 12 portions. Using buttered hands, shape each portion into pumpkin shape around one candy piece. Pipe frosting onto each for vines and attach gumdrop for stem.