Easy Lime Pie
["1 graham cracker or chocolate pie crust", "1 (12 oz.) can frozen limeade concentrate, thawed", "1 (14 oz.) can sweetened condensed milk", "1 (8 oz.) container Cool Whip", "3/4 c. sour cream (optional)", "1 small container Cool Whip *", "several drops green food coloring"]
["In large bowl, combine limeade (undiluted) and condensed milk; mix well.", "If using sour cream, do so at this time.", "Add a few drops of green food coloring and fold in whipped topping.", "Pour mixture into pie crust.", "Chill until set."]
["graham cracker", "frozen limeade", "condensed milk", "sour cream", "*", "several drops"]