Sprinkle gelatin over 1/2 cup orange juice and let stand. Oil a 10 inch tube pan.
Beat the egg yolks with 3/4 cup sugar. Beat in lemon juice and remaining 1/2 cup orange juice. Transfer to a small saucepan and cook over low heat, stirring constantly, until mixture thickens enough to coat the back of a spoon. Remove from heat and stir in gelatin mixture.
Beat the egg whites with 3/4 cup sugar until stiff. Fold hot custard into egg whites. Fold in cake pieces and pineapple. Pour mixture into prepared pan. Place cherry halves with a spoon throughout the mixture. Chill in refrigerator overnight.
In a chilled bowl, whip cream, green food coloring and 2 tablespoons sugar with an electric mixer until stiff. Serve unmolded dessert with whipped cream.