Yellow vests aren’t just for crossing guards or French protesters anymore: They’re being sported on Denver’s streets by so-called Yellow Vest Ambassadors, the centerpiece of Mayor Mike Johnston’s Clean and Safe Downtown Initiative. The ambassadors range from city employees to members of the Downtown Denver Partnership (DDP), property managers, business owners, representatives of registered neighborhood organizations and workers with the Denver Dream Center — a nonprofit that helps those experiencing homelessness, hunger, poverty, addiction or abuse…