Melt the Marshmallows as you would for Rice Crispy treats. Add green food coloring until it is a desirable shade. Pour entire box of Cornflakes into a large bowl. Carefully pour entire warm Marshmallow mixture over the cornflakes, and using your hands or a spatula, mix until all are evenly coated. Form into wreaths on plates. Do not let wreaths touch as they cool. Decorate with red. This is a great recipe to share with the kids or grand kids.