Laugh O. Grams said:
You are very fortunate, as most white gold will tend to yellow. White gold is a mix of pure gold with copper, silver and either nickel or palladium. These days, most white gold is rhodium treated. Rhodium is a hard and durable metal often used on white gold to emphasize the white color. Chlorine is especially hard on white gold, and in some cases, can even turn white gold black!