Preheat oven to 350°F and grease three 8-inch round cake pans.

In a large bowl, whisk together flour, sugar, baking powder, and salt.

Add melted butter, eggs, buttermilk, and vanilla extract; beat until smooth.

Divide batter evenly into three bowls and tint each with different food coloring.

Layer each colored batter into the prepared pans to form concentric rings.

Bake for 20 minutes or until a toothpick inserted into the center comes out clean.

Allow cakes to cool completely before frosting with your choice of icing.