Dress up the tried-and-true rice crispy treat recipe by adding a little food coloring. Instead of the standard bars, try cutting them out with your star-shaped cookie cutter. When it comes to adding the food coloring, Wilton icing color is your best bet. Apply it by dipping a toothpick in the jar of color and then mixing it into the marshmallow mixture. Other food colorings can occasionally change the texture of the marshmallow mixture.