In a larger bowl, melt the mini marshmallows and butter. Add the cereal and red food coloring to desired color. Press the cereal into the center of the pan and, with your hands, press down to pack all three colors together. Place the chocolate chips, flat side up, randomly in the red fruit part of the watermelon. Let harden. Cut into wedges. For wedges on a stick, insert a stick into the wedge while the cereal mixture is still soft.