Have you looked into cad plating? I had some large bits done many years back that had a golden (yellow) finish that would have buffed up to a similar finish.
Bright Nickel plating can also have a yellow finish.
I buffed my WCS pieces up an I am sure they were definately plated not painted but I am unsure what technique was used, I suspect cad 

There are also products such as this:



but I am unsure how they would go with a ball rubbing against them over and over. I would go for plating and only use paint as a last resort the plating is much harder and better suited for the application