1. Sprinkle gelatin over water in medium saucepan; let stand 2 minutes to soften. Cook over low heat, stirring constantly, until gelatin is completely dissolved, about 3 minutes. Stir together sugar and cocoa in small bowl; add gradually to gelatin mixture, stirring with whisk until well blended. Continue to cook over low heat, stirring constantly, until sugar is dissolved, about 3 minutes. Remove from heat. Stir in evaporated milk and vanilla. Pour mixture into large bowl. Refrigerate, stirring occasionally, until mixture mounds slightly when dropped from spoon, about 2 hours.
2. Fold 1/2 cup whipped topping into chocolate mixture. Divide about half of mixture evenly among 8 parfait or wine glasses. Stir extract and food color into remaining 1-1/2 cups topping; divide evenly among glasses. Spoon remaining chocolate mixture over topping in each glass. Garnish as desired. Serve immediately or cover and refrigerate until serving time.