PLACE each flavor of gelatin in separate medium bowl. Add 1-1/2 cups of the boiling water to gelatin in each bowl; stir at least 2 minutes until gelatin is dissolved. Stir 1 cup of the cold water into dissolved gelatin in each bowl.
SPRAY Uncle Sam's Mold with no stick cooking spray; place on baking sheet. Pour blue gelatin into the side of the prepared mold with the stars; pour red gelatin into remaining side with the stripes.
REFRIGERATE 6 hours or overnight until firm. Unmold. Decorate with whipped topping as desired.
KITCHENS TIPS :
How To Unmold Gelatin: Allow gelatin to set until completely firm, several hours or overnight. Before unmolding, dip knife in warm water and run knife around edge of gelatin to loosen. Dip mold in warm water, just to rim, for 15 seconds. Lift from water and gently pull gelatin from edge of mold with moist fingers. Place moistened serving plate on top of mold. Invert mold and plate and shake to loosen gelatin. Gently remove mold.