Cook the pasta according to the package directions; drain.
Meanwhile, melt the butter in a large saucepan over medium heat. Whisk in the flour and cook for 2 minutes. Gradually add in the milk and cook, whisking now and then, until slightly thickened. Whisk in the Worcestershire, mustard powder, paprika, salt, and pepper. Reduce the heat to low and whisk in the cheeses until smooth.
Add the drained pasta and stir until mixed.
Tip: To make this into a baked casserole, increase the milk to 2¼ cups and pour the cooked mac and cheese into a 2½-quart baking dish. Top with ¼ cup of seasoned bread crumbs and coat the casserole with cooking spray. Bake at 375°F until golden and bubbly, about 20 minutes.