In bowl, beat egg yolks. Gradually beat in milk and lime juice. Stir in food coloring.Pour into pie crust and bake 325 degrees for 30 minutes. Take out. Put oven on to 350 degrees. In bowl, beat egg whites, cream of tartar until soft peaks form. Add sugar, beat in. Put meringue on top of pie and brown in oven (watch it, each oven is different. We're talking minutes.)Chill for 3 hours before serving.
NOTE: I put my bowl and beaters that I am going to use to make the meringue in the freezer while the pie is in the first 30 minutes. It's easier to get the egg whites to peak.