White for all Chiefs, Red for LT's and Captains, and Black for Firefighters. We keep it pretty simple. We do this so a member can be easily recognized on scene. The Chief should stand out as command to incoming companies. The LT's and Captains should stand out to the firefighters. The firefighters should not have to be mistaken for one of the Officers.
The helmet colors on my dept. is White are Chiefs, Red are Captains, Yellow are Lieutenants, Blue is our EMS Officer, Green is Safety, Black are Firefighters.
Black --- Explorers
Yellow -- Firefighters/ Firefighter Paramedics (without a shield is a Rookie)
Orange-- Capt.
Red --- Arson Investigators
White --- Chiefs
Blue ---- Single Function Paramedics (not Firefighters)<--very uncommon, in 2+ years i have only seen it
once