Preheat oven to 350 degrees Fahrenheit

In a pot of salted boiling water cook the macaroni until it is al dente.

In a skillet cook bacon over medium heat until crispy. Remove from fat and crumble. Sauté onion & peppers in fat until onions become translucent.

Drain pasta. In a large pot over low-medium heat, melt the butter, being careful to not let it burn. If it starts to bubble, then add some of the milk to keep it from burning. Add the cream cheese and stir it around to help it melt. A handful at a time add up to ¾ of the grated cheeses and continue to mix the cheese to help it melt slowly. Add the rest of the milk to help the mix become creamy.  When the cheese mix is smooth and creamy add in the pasta, onion/pepper mix and the bacon. Mix so the macaroni is evenly coated and pour into a casserole dish. Top with remaining cheeses.