mbenz,
From research, the first turquoise hydrants were painted at the request of a former mayor's wife to beautify the city.
Turquiose HydrantsCurrently, the hydrants are actually color coded wherby red, yellow, and blue signify the pipe size attached to the hydrant. This "color code" enables firefighters to accuratly choose the most appropriate hydrant when fighting a fire.
Chronicle-Tribune.comPlease let me know if you have any additional questions.
Beest of luck,
Liddy Bea
If you are satisfied with my solution, please click, "Accept." If you need further assistance, please let me know. Thank You :-)