Preheat your oven to 350°F (175°C). In a large bowl, combine the white cake mix with the milk, mixing until smooth. Divide the batter into individual bowls and add food coloring to each bowl until colors are vibrant.

Grease a 9x13 inch baking dish. Spoon the colorful batter into the dish, swirling the different colors together. Bake for 25–30 minutes, or until golden and a toothpick comes out clean. Cool in the pan for 10 minutes.

Poke holes all over the top of the cooled cake using a wooden spoon handle or skewer, spacing them about an inch apart.

In a separate bowl, whisk the instant pudding mix and milk until smooth and thick. Pour the pudding evenly over the cake, filling the holes.

Cover with plastic wrap and refrigerate for at least 2 hours to allow the pudding to set.

Chill a mixing bowl for 10 minutes, then combine heavy cream and powdered sugar in it. Whip until soft peaks form, which takes 3-5 minutes.

Spread the whipped cream evenly over the chilled cake. Decorate with colorful sprinkles or edible glitter before serving.