Heat oven to 450°F. Bake pie crust as directed on box for One-Crust Baked Shell, using 9-inch glass pie plate. Cool on cooling rack 15 minutes.
Spread raspberry sherbet in pie crust. Freeze about 20 minutes or until almost firm. Repeat layering with orange and lemon sherbets, returning to freezer after each layer.
Spread whipped topping over sherbet, leaving about 1 inch of lemon showing around edge of crust. Garnish pie with sprinkles around outside edge. Cover loosely; freeze 2 hours before serving.