McDonald's original Golden Arches were yellow.
The arches were developed from the architectural design of early McDonald's restaurants, where large yellow arches stood at either side of the building. Their bright color helped the restaurants attract attention from passing motorists and made the buildings easy to identify.
The arches began as physical architectural features rather than a fully abstract corporate logo. Over time, the design was simplified and combined into the familiar golden M used on signs, packaging, uniforms, and advertising.
Yellow is sometimes confused with later McDonald's color combinations, especially the red-and-yellow scheme used across restaurant exteriors and promotional materials. The defining color of the arches themselves, however, is gold or yellow, which explains the name “Golden Arches.”