Filling: Mix sugar and cornstarch in 2 quart saucepan. Stir in water gradually. Cook over medium heat, stirring constantly until mixture thickens and boils. Cook and stir 1 minute.

Remove from heat and stir half of the hot mixture quickly into beaten egg yolks, then blend into remaining hot mixture in saucepan. Reheat to boiling; cook and stir 1 minute.

Remove from heat; stir in butter, food color and lime juice, mixing well. Pour into baked pie crust.

Meringue: With electric mixer, beat egg whites and cream of tartar until foamy. Beat in sugar, 1 tablespoon at a time; continue beating until stiff and glossy. Add vanilla. Do not under beat.

Spoon meringue onto hot pie filling; spread over filling, spreading meringue to edge of crust and adhering to prevent shrinking.

Bake in a preheated oven at 400° on center rack of oven for about 5 to 7 minutes, or until a delicate golden brown. Cool draft free for 1 hour, then refrigerate for 3 to 4 hours before serving