Preheat oven according to the cake mix instructions. Grease and flour a 9x13-inch baking dish.

Prepare the white cake batter according to the package directions.

Divide the batter into separate bowls, depending on how many pastel colors you want to use. Add a small amount of gel food coloring to each and mix well.

Pour the colored batters in layers or swirls into the baking dish, using a spoon or skewer to create a marbled effect.

Bake according to the package instructions, then let it cool completely.

While the cake cools, prepare the pudding by whisking the pudding mix with milk until it thickens.

Once the cake is cooled, poke holes all over the surface using the handle of a wooden spoon.

Pour the prepared pudding over the cake, spreading it evenly and allowing it to seep into the holes.

Spread Cool Whip over the pudding layer.

Garnish with Easter-themed sprinkles.

Chill for at least 2 hours before serving to let the flavors set.