Here are pics of Washington, DC metro police with sky blue helmets on their heads:
Sky blue is the color that United Nation troops wear on their heads, whether helmet or beret:
.To my knowledge, DC metro police are the only police in the U.S. who wear the same blue-colored helmets as the UN.
Here are pics of the police riot gear of three U.S. cities: Boston, Dallas, and Seattle. Notice that their helmets are all black in color, not blue.
H/t FOTM’s Miss May
~Eowyn