Wanderlust World Wanderlust World The Statue of Liberty's iconic green hue is a natural patina—a layer of copper carbonate formed when the statue's copper skin reacts with oxygen, moisture, and atmospheric compounds (like carbon dioxide and sulfur) over decades. This patina protects the underlying copper from further corrosion. Originally unveiled in 1886 with a shiny brown copper surface, the statue gradually turned green by the early 1900s. The patina is now a stable, protective coating integral to the monument's preservation.