Line unpricked pastry shell with a double thickness of heavy-duty foil.
Bake at 450 degrees for 8 minutes.
Remove foil; bake 5 minutes longer.
Cool on a wire rack.
In a saucepan, combine 3/4 cup sugar, cornstarch and salt. Stir in water; bring to a boil over medium-high heat. Reduce heat; add remaining sugar. Cook and stir for 2 minutes or until thickened and bubbly.
Remove from the heat; stir in butter, lemon peel and food coloring if desired.
Gently stir in lemon juice (do not overmix).
Cool to room temperature, about 1 hour. Do not stir.
In a mixing bowl, beat cream cheese and sugar until smooth.
Fold in whipped topping and lemon juice. Refrigerate 1/2 cup for garnish.
Spread remaining cream cheese mixture into shell; top with lemon filling.
Place reserved cream cheese mixture in a pastry bag with a #21 star tip; pipe stars onto pie.