In a large Dutch oven, melt butter over medium heat.
Slowly add marshmallows, stirring until completely melted.
Blend cake mix and food coloring into marshmallow mixture. Stir in rice cereal until it is completely coated with marshmallow mixture.
Pour cereal mixture into a greased 13x9x2 pan. Let cool at room temperature before serving. To make cookie cutter shapes, refrigerated mixture until hardened. Use cookie cutter coated with non-stick spray. Bring treats back to room temperature before serving.