Is the blue dye in porta potties required for odor control?

I'm renting a standard unit for a three-day weekend event on my property. The ground is level and the vacuum truck has easy access for the weekly service visit. I've noticed the distinctive blue liquid in the holding tank after each service. It makes me wonder: is that blue dye actually required for odor control, or is it just for appearance? The blue color is so universal, but I'm curious if there are any alternatives that work just as well without the dye. Is the dye itself part of the chemical formula that breaks down waste, or could a company use a clear or differently colored deodorizer that works just as effectively?