STIR 1 cup of the boiling water into each of the red and blue gelatins in separate medium bowls at least 2 minutes until completely dissolved. Stir 1/2 cup of the cold water into each bowl.
PLACE bowl of red gelatin in larger bowl of ice and water. Stir about 8 minutes or until thickened. Stir in strawberries. Pour into 9x5-inch loaf pan sprayed with cooking spray. Refrigerate 7 minutes.
MEANWHILE, stir remaining 3/4 cup boiling water into lemon gelatin in medium bowl at least 2 minutes until completely dissolved. Stir in ice cream until melted and smooth. Spoon over red gelatin in pan. Refrigerate 7 minutes.
MEANWHILE, place bowl of blue gelatin in larger bowl of ice and water. Stir about 7 minutes or until thickened. Stir in blueberries. Spoon over lemon gelatin in pan.
REFRIGERATE 4 hours or overnight until firm. Unmold. Cut into 16 slices. Store leftover gelatin mold in refrigerator.