Key Lime Pie
["1 can condensed milk (14 oz.)", "4 eggs (use egg yolks only)", "1/2 c. lime juice", "2 drops green food coloring (optional) *", "1 graham cracker pie crust", "1 (8 oz.) container Cool Whip"]
["*Can add food coloring to mixture, if you desire)"]
["condensed milk", "eggs", "lime juice", "coloring", "graham cracker pie crust"]