Lightly roll out pastry into a 12" circle; transfer to a 9" pin plate. Trim pastry to 1/2" beyond edge of plate, Flute edges. Line unpricked pastry shell with a double thickness of heavy duty foil. Bake at 450* for 8 minutes. Remove foil and bake 5 minutes longer, cool on wire rack.
In a large saucepan, combine the sugar, cornstarch and salt. Stir in water until blended. Bring to a boil; cook and stir for 2 minutes or until very thick. Remoe from heat; stir in butter, lemon peel, and food coloring if desired. Gently stir in 1/2 cup lemon juice. Cool to room temperature, about 1 hour.
In a large mixing bowl, beat cream cheese, powdered sugar, until smooth. Fold in whipped topping and remaing lemon juice. Spread into crust; top with lemon filling. Refrigerate for at least 6 hours or until the top is set.