In a small saucepan, combine the onion, vinegar, and sugar and bring to a simmer, stirring often, for about 2-3 minutes.
Remove the onion from the pan and fill it with water to cook the noodles as directed, rinsing the noodles when they are done.
Meanwhile, coarsely chop one egg.
Separate the white from the yolks on the remaining 5 eggs.
Place the yolks aside and coarsely chop the egg whites.
Make the dressing by mashing the egg yolks in a small bowl and adding the mayonnaise, Dijon mustard, and paprika.
If the dressing is too thick, add up to 2 tbsp. of water to thin it down.
Taste and add salt and pepper if desired.
In a large bowl, toss the egg whites with the cooked macaroni noodles and fold in the dressing
Top with reserved egg and garnish with green onion if desired