Prepare a souffle' dish by forming a 3" collar of waxed paper around the top edge of the dish.
Press waxed paper strip against lightly greased inside of dish.
Allow to extend 2 inches above the dish.
Combine gelatin,1/2 cup sugar and salt .Add water.Beat yolks slightly and blend in.
Microwave 4 to 5 minutes until mixture bubbles,stirring every 2 minutes.
Beat smooth.Stir in lime peel and juice.Cool until thickened but not set.
Add food coloring.Beat egg whites until frothy.
Gradually add 1/4 cup sugar and beat to soft peaks;set aside.
Whip cream until thick;stir in 1/4 cup sugar.
Fold cream and gelatin into egg whites.Spoon into souffle' dish.
Refrigerate 4 hours.Remove collar and serve.