I do the white/cheese sauce version but always add a 1 tsp of dry mustard powder when making the roux. Sprinkle with a little Paprika before putting under the grill (broiler?)

And diced up fatty smoked bacon, fried up with a chopped fine Red onion (dry-fry together - the fat from the bacon is sufficent to cook the onion together with it) is lovely stirred in.

Bacon makes it fairly salty so, apart from the salt to cook the pasta with, don't add any more to the sauce.

Serve with vine-ripened tomato salad .. a little Olive oil and black pepper dressing