Begin by preheating your oven to 350°F (175°C) and greasing a 9x13-inch baking dish. In a large bowl, prepare the cake mix as per instructions, then divide the batter into four portions and add food coloring.

Spoon the colored batter into the baking dish randomly, swirl gently with a toothpick, and bake for 25–30 minutes or until a toothpick comes out clean.

After baking, allow the cake to cool for 10 minutes in the pan then transfer to a wire rack. Poke holes in the cake using a wooden spoon handle.

In another bowl, whisk together the pudding mix and milk until thickened, and pour it over the cooled cake, ensuring to fill the holes. Refrigerate for at least 2 hours.

Whip heavy cream and powdered sugar until stiff peaks form and spread it over the cake.

Optionally, garnish the cake with colorful candy or sprinkles before serving.