Lime or Lemon Pie

1 can frozen limeade
1 can sweetened condensed milk
Green food coloring
3/4 cup sour cream
1 (8 ounce) container Cool Whip

Combine the limeade and condensed milk. Add food coloring and sour cream. Fold in Cool Whip. Pour into prepared pie shell. Chill. Garnish before serving.