Combine crumbs, sugar and margarine; press onto bottom of 9-inch springform pan. Bake at 325 degrees F for 10 minutes. Cool.
Soften gelatine in water; stir over low heat until dissolved. Add juice, egg yolks, 1/4 cup sugar and peel; cook, stirring constantly, over medium heat for 5 minutes. Cool.
Gradually add gelatine mixture to Neufchatel cheese, mixing at medium speed of electric mixer until well blended. Stir in food coloring.
Beat egg whites until foamy. Gradually add remaining sugar, beating until stiff peaks form. Fold egg whites and whipped topping into Neufchatel cheese mixture; pour over crust. Chill until firm. Garnish with additional lime peel, if desired.
Source: E-Cookbooks.net