Add 1 can of sweetened condensed milk with 1/2 cup white cake mix. Then add 2 cups of the white chocolate chips and mix.
Microwave the mixture in a microwave-safe bowl for 1 minute, then remove and stir. If the chocolate chips are not melted, return and heat for 20 seconds. Don't overheat, though - this will burn the chocolate. Once melted, add 1/2 teaspoon of vanilla and mix.
Divide the mixture between two bowls. In one bowl, add the blue food coloring.
In the other bowl, add the red food coloring.
Repeat the first steps (minus adding the food coloring) with the rest of the ingredients. Let the mixture cool, then fold in about 1/4 cup of sprinkles. Cooling is important so that the sprinkles don't melt or bleed.
Pour the blue mixture into a baking dish lined with foil. Smooth it out evenly to cover the dish.
Add the white mixture with sprinkles on top of the blue and smooth it out. Then add the red, and smooth it out.
Sprinkle about 1/4 cup of sprinkles on top and use your hand to pat them down lightly.
Put the pan in the fridge for at least 2 hours. Remove, cut, and enjoy.