What is the official color of the Golden Gate Bridge?

Answer

It was chosen partly to be visible in fog.

Context

The bridge's color began with its primer. The steel arrived coated in a red lead primer, and the consulting architect Irving F. Morrow, who shaped much of the bridge's look, liked the effect as the towers rose. He studied several options and settled on a deeper orange-red that suited the surrounding hills and stood out against the sea and sky. According to the bridge district, black, grey and aluminum were considered and rejected, and a warm grey was the runner-up.

The name International Orange is older than the bridge. It is a color used in aerospace and other fields to make objects stand out sharply from their surroundings, and it is sometimes associated with high-visibility safety gear. The bridge's orange was chosen specifically as a paint, and the hue is often described as a slightly different formulation from the aerospace standard, so the two should not be assumed to be identical.

Visibility in the frequent San Francisco fog is an often-cited benefit, since the warm color contrasts with a grey background and helps ships see the structure. A popular story says the U.S. Navy wanted black and yellow stripes for that reason; the district's color page does not mention this, so it is best treated as unconfirmed folklore. Another misconception is that the bridge is simply left in its original shade. The district maintains the color with continuing paint work, including touch-ups and recoating over the years, to protect the steel from the salty marine air.