1 (6 oz.) can frozen limeade concentrate, thawed
1 (14 oz.) can sweetened condensed milk
A few drops of green food coloring
1 (8 oz.) carton frozen whipped topping, thawed
1 (9 oz.) graham cracker crumb pie crust

Mix limeade concentrate and sweetened condensed milk in a bowl. Whisk until blended. Whisk in food coloring, blend well. Fold in dessert topping. Turn mixture into pie crust. Refrigerate until firm, about 3 hours. Garnish with additional whipped topping and lime slices.