Why Boeing Airliners Are Painted Emerald Green Before Delivery

The Boeing aircraft production process involves several stages, including final assembly and painting. Before receiving its airline livery, an airliner is painted a glossy emerald green color, which is actually a primer intended to protect the aluminum alloy used in its construction.

This primer, made with zinc-chromate coating, was pioneered by Ford in the 1920s for use in the automotive industry. Today, it's most heavily used in aviation to safeguard against corrosion and metal fatigue.

The green paint is yellow-based, but lampblack is added to protect against ultraviolet light from the sun, resulting in a green color. The primer is applied during production of various aircraft components, which are then shipped to final assembly still wearing this green color.