Chicago Hot Dog Relish | Neon Green Sweet Relish

What is with that neon green relish on a Chicago hot dog?

Best known story that I can find is that a sweet relish manufacturer dyed his product to cover up some lighter green relish. What is more Chicago history than a snake oil salesman?!

Anyway, it became a necessity for Chicago Hot Dogs, along with yellow mustard, sport peppers, tomato wedges, celery salt, diced onion, & a dill pickle spear. So "Getcha Hot Dog He'ya!"