PURPOSE: To manufacture an ornamental multicolor gold alloy which is greenish gold or pinkish gold by adhering silver or copper, etc. on gold or a gold alloy in an optional pattern, and treating said alloy in a nonoxidizing atmosphere with thermal diffusion.

CONSTITUTION: An adhered layer of silver or copper or silver and copper is formed on the surface of pure gold such as 24K, 18K, and 14K or a gold alloy in an optional pattern with electrolytic plating, electroless plating, vacuum deposition, spattering, ion plating, flame spraying, etc. by using a common plating resist, a masking agent, or a photoresist. The obtained body is heated in a nonoxidizing atmosphere at 300W700°C, and a golden ornamental pattern which is greenish gold and pinkish gold other than original gold of the gold itself is formed with good adhesion.