Using a mixer, beat cream cheese until fluffy. Gradually beat in sweetened condensed milk until smooth. Stir in food coloring and the crushed Mint Krispys (save 1/4 to sprinkle on top). Fold in whipped topping. Pour into crust. Place in freezer until firm. Garnish as desired with crushed Mint Krispys. Store leftovers in freezer. Serves 8.