Cook macaroni according to package directions.
While macaroni is cooking pour 1/3 cup buffalo sauce on top of shredded chicken and mix well.
When macaroni is done cooking, drain and in the same pot, over medium heat, melt butter and whisk in flour cooking for about one minute, stirring constantly.
Add in milk, cheddar, Monterey Jack cheese.
Stir frequently until cheese has completely melted into a sauce.
Add salt and pepper to taste.
Combine cooked macaroni and shredded chicken in the pan with the sauce.
Serve warm topped with freshly chopped parsley and blue cheese crumbles.