In a large pot, bring water to a boil. Cook macaroni according to package directions for al dente pasta. Drain, rinse with cold water, and allow to cool to room temperature.
In a small bowl, add mayonnaise, lemon juice, mustard, salt, pepper, garlic powder, and paprika. Whisk to combine.
In a large bowl, add macaroni, onion, celery, bell pepper, and eggs. Add dressing and toss to evenly coat all ingredients.
Pour macaroni salad into a serving dish and top with chopped parsley. Serve immediately, or cover and refrigerate until ready to serve.
Your macaroni salad can be made the same day, or the day prior to serving. I'd recommend at least an hour of chilling in the refrigerator to allow all of your ingredients to cool and flavors to meld, but it can be served immediately.
Red bell pepper can be substituted with green, yellow, or orange bell pepper, or pimientos instead.
Optionally, sprinkle extra paprika on top as a decoration.