The alloy commonly used to make white gold has typically been
nickle. Yes, it turns the yellow gold white ( mostly) but is tricky
to work with. A really tough metal. I recommend palladium as the
to alloy with pure gold to get 18K or 14K white gold. Yes, it is more
expensive, but a much better white (no rhodium plating required) and
a real pleasure to work with. I’ve pretty much given up nickle-based
white gold alloys in favor of palladium alloys. Far superior in every
way, to my experience.