Preheat oven to 350 degrees. Lightly grease a 13 x 9-inch baking dish.
Cook noodles according to package directions and drain. Place noodles in a large bowl.
Meanwhile, in a saucepan over medium heat, melt the butter. Slowly add flour, stirring constantly to make a rue. Whisk in milk until well combined.
Stir in cream cheese, Colby and cheddar cheeses. Season with garlic powder, onion powder, salt and pepper. Bring to a boil stirring constantly. Pour cheese sauce over the noodles; stir to combine.
Pour mac and cheese into the prepared baking dish. Cover and bake for 15 minutes. Crush Ritz and place over the top of noodles, bake an additional 15 minutes uncovered. Serve immediately.