Original hardware was probably cadmium plated, but now hard and very expensive to get done. I have a connection at a commercial zinc plater, who can do it in either a bluish tint or goldish tint. I take about half a Home Depot bucket's worth at a time, and he does it for less than $150.
And it is A LOT of hardware - axles, spacers, exhaust split collars, brake rods and brake shoe cams, brake anchor arm, even tool kit tools and rear footpegs (complete with the rubber - it doesn't affect it). I've tossed all my old hardware in and they come back looking new, saving me hundreds over the years.