Why are D.C.’s fire hydrants green? Doesn’t it make harder for firefighters to find them? It certainly makes it harder for me to notice them when I’m trying to find a parking spot.

The majority of the District’s fire hydrants have been the same shade of green for more than 100 years, according to Louis Jarvis, director of the District of Columbia Water and Sewer Authority.

The reasoning? While green is harder to see than the more common red or yellow, it sure is pretty. “Although they’re less visible than other colors, they are aesthetically pleasing,” he says.

The reason that aesthetics can rule over practicality is that District firefighters are supposed to know where the hydrants are. The “layout” firefighter in a given unit, who is in charge of attaching the fire hose to the hydrant—as well as numerous backup layout firefighters—knows the location of a significant portion of the District’s more than 8,700 hydrants—including every hydrant in their service area.

Interestingly, within the past five years, the District’s fire department pondered changing the color of the hydrants, but decided against it rather than change the look of the District’s tree-box areas.

In case you’re wondering, there’s no significance to the occasional yellow and red hydrants that dot the city. That’s just the way they’ve always been, says Jarvis.

Every Monday, the ‘Huh?’ Bub takes your questions. Got one?