5 HRS 25 MIN
Add 1-1/2 cups boiling water to blue gelatin mix in medium bowl; stir 2 min. until completely dissolved. Repeat in separate bowl with red gelatin. Stir 1-1/2 cups cold water into gelatin in each bowl.
Spray 10-cup flag mold with cooking spray; place on baking sheet. Pour red gelatin into mold. Refrigerate 45 min. until set but not firm. Meanwhile, refrigerate blue gelatin 45 min. After 20 min., dissolve lemon gelatin in boiling water in separate bowl. Refrigerate 25 min. or until slightly thickened.
Whisk COOL WHIP into lemon gelatin; spread over red gelatin layer in mold. Refrigerate 10 min. or until set but not firm. Cover with blue gelatin. Refrigerate 4 hours or until firm. Unmold.