I would’ve left the the durned things silverish—if they’d shown any inclination to stop shedding paint. The inside of the box in which the M12-bolt “shelf feet” had been shipped to me was speckled with the stuff and it rubbed off onto my hands readily.
The pegboard/storage wall units that I’m installing in my shop came with “feet”, but the diameter of their inverted metal cups, the parts holding the black rubber annular pads that make contact with the floor, were too large for my application. Off I went, hitting up a Taobao shop from which I’d purchased feet for other storage units in the past.
A few days after paying for plain (i.e. “clear zinc” plated) steel shelf feet with smaller-diameter cups, I received a box of “yellow zinc” plated shelf feet. On their own initiative, the seller had spray painted them silver and done a slapdash job of it. Since the paint wasn’t adhering well, anyway, I soaked one with WD-40 and rubbed at it with a paper towel. Nearly all of the silver came off in a matter of moments, though a few patches clung stubbornly here and there to the screw threads. Before subjecting the rest of the feet to the same treatment and installing them as intended, I snapped the photo above.