In a large bowl, whisk together sweetened condensed milk and lemon juice. Stir in mini marshmallows, cranberry sauce, crushed pineapple, chopped pecans and food coloring. Fold in whipped topping until no streaks remain.
Spoon into a 13 x 9 x 2-inch baking dish. Freeze until firm, about 4 hours or overnight. Cut into squares and serve. Makes 18 servings.