Sprinkle gelatin over water; let stand 5min. Combine 1/2c sugar,egg yolks,and guava juice in a pot cook on med. heat until thickened. Add gelatin and stir to combine add lemon juice and food coloring and cool completely.
Beat egg whites with salt until foamy; add 1/4c sugar gradually, beating until stiff and holding peaks. Fold the cooled guava mixture into the meringue. Chill at least 4 hours top with sweetened whipped cream.