Spread corn flake cereal on a baking sheet. Heat marshmallows, margarine, vanilla and food coloring in a double boiler until marshmallows melt. Carefully pour marshmallow mixture over cereal. Blend well and, as mixture cools, spoon 2 tablespoons of mixture onto wax paper. Form cereal mixture into a wreath shape. Arrange candies on top of each wreath to resemble holly berries. Allow wreaths to set up.