Slice eggs in half and scoop out the yolk into a mixing bowl. Set the whites aside, cut side up onto a serving plate. Mash yolk with a fork. Add mayonnaise, mustard, salt and pepper and mix well. Add food coloring and mix until orange.
Use a spoon to spoon a dollop of the egg mixture into each egg. Shape it so it's round. Tuck a small celery in the top to look like a stem.
Serve immediately or cover and refrigerate until ready to serve.