Prepare the cake according to the box directions. Add the water, vegetable oil, and egg whites to the mix and stir until combined.
Bake for 28 to 33 minutes (or until donas instructed by the directions on the box. Let the cake cool completely.
Once the cake is cooled completely, take a wooden spoon with a round handle and poke holes into the cake. Be generous with adding holes to the cake. Set the cake aside.
Add the red jello mix to a small bowl. Add ½ cup of boiling water to the red jello mix and stir until the granules are dissolved.
Add the blue jello mix to a separate small bowl. Add ½ cup of boiling water to the blue jello mix and stir until the granules are dissolved.
Carefully spoon jello mixtures into the holes alternating the colors, trying to only pour one color into each hole. If two colors get it one hole, you'll have a purple cake instead of a red white and blue poke cake.
Place the cake in the fridge for about 30 minutes to allow the jello to soak in.
Frost the cake with whipped topping or a sweetened whipped cream. Sprinkle some festive sprinkles on top of the cake just before serving.