Preheat oven to 400 degrees.
Cube the colby cheese into small cubes.
Add the cooked pasta to a baking dish.
Puncture the lid of the evaporated milk can and pour over the pasta, distributing evenly.
Add a tablespoon of margarine near each of the 4 corners of the baking dish.
Gradually add the colby cubes, stirring constantly so that they're evenly distributed throughout the pasta.
Sprinkle shredded cheddar cheese on top of the pasta.
Cover with foil and place in the oven.
Check on the macaroni and stir ocassionally.
Leave in the oven for 40-50 minutes, or until the evaporated milk on the bottom starts to solidify!