What causes gold to be different colors?
While pure gold is a warm yellow, it can be manufactured in a wide variety of colors-including pink, white, green, blue or gray-by being mixed with different metals. For example, when silver and copper are added to pure gold, it turns yellow. When nickel or palladium (or zinc and copper) are added, gold turns white. Pure gold combined with silver, copper and zinc results in green gold. And pink gold is made when copper is mixed with pure gold.
