Cook elbow macaroni in salted boiling water until al dente; drain and rinse under cold water.
In a large bowl, combine mayonnaise and sour cream to create the dressing.
Add diced green onions, bell peppers, carrots, and pineapple to the dressing.
Stir in sweet pickle relish and mix well.
Add the cooled macaroni to the bowl and toss to combine.
Season with salt and pepper to taste.
If using, fold in cooked ham or shredded chicken.
Cover and refrigerate for at least 1 hour.
Serve chilled, garnished with additional green onions if desired.