Dissolve each flavor of jello completely in 2 cups of boing water inseparate bowls. Stir 1 cup of cold water into each bowl. Pour into separate9x13 inch pans. Refrigerate at least 3 hours until firm.

Cut into 1/2 inch cubes. Place blue jello cubes in bottom of clear glass trifle bowl. Top with 1/3 of the Cool Whip. Add cake cubes, then sliced strawberries. Top with another 1/3 Cool Whip. Add the red jello cubes and then the remaining Cool Whip. Sprinkle blueberries over top if desired.

Refrigerate before serving.