White 18ct gold has been use for years in UK for setting diamonds in engagement rings combind with 22ct yellow gold.
White 18ct gold claws are harder wearing something as to hold the diamond in place.
A white gold diamond setting can be set in 9ct gold ring designs as well if savings are to be made.
My wife prefers the darker yellow gold here which she calls old gold.
I guess machines are handy these days we always used acids and an eye glass.