Recently a client came in with this family heirloom ring.
We were able to rhodium plate it to change it from yellow gold to look like white gold (see the difference in the before/after photo below).
This is a process I wouldn’t normally recommend, because it will wear away and change back to its yellow gold colour, as the plating is reasonably soft. But it can be worn as a dress piece rather than an every day piece to make the colour last longer, and it is a process that can be done multiple times to keep it looking good without harming the ring.
Normally we would have taken the head off and put it onto a new white gold ring, but because this is an heirloom piece we didn’t want to replace any of the original ring if necessary. It also allows the ring to go back to it’s original colour for anyone who inherits it in the future and may prefer the yellow gold look.