Mix and bake the cake according to box directions in a 13 x 9 baking dish. Let the cake cool completely before the next step.
Use a wooden spoon to poke holes all over the cake.
Prepare box jello with one cup of hot water and ½ cup of cold water.
Use a spoon and pour the red jello into holes all over, then do the same with blue jello. Make sure not to pour both jello colors in the same hole or you will end up with purple cake instead of Red and blue.
Refrigerate the cake for 3-4 hours or overnight for the jello to set up.
Then top the cake with the whipped topping.
Use a toothpick and swirl the red and blue food coloring all over the top of the whipped cream if you want to.
Use different Red White and blue sprinkles to decorate the cake.