Preheat the oven to 350°F (175°C). Grease a 9×13-inch baking dish.
Cook the elbow macaroni according to package instructions until al dente. Drain and set aside.
In a large saucepan, melt the butter over medium heat. Whisk in the flour and cook for 1-2 minutes until lightly golden.
Gradually whisk in the milk, stirring constantly until the mixture thickens, about 5 minutes. Add salt, pepper, and paprika.
Remove from heat and stir in 2 cups cheddar, mozzarella, and Parmesan cheese until melted and smooth.
Combine the cooked macaroni with the cheese sauce and pour into the prepared baking dish. Top with remaining cheddar cheese and panko breadcrumbs.
Bake for 25-30 minutes until the top is golden and bubbly. Let cool slightly before serving.