The jack base, jack hook, jacking mechanism are all painted semi gloss black.
the jack handle is also semi gloss black.
The jack post and tire hold down & hold down handle ( not in your picture) are zinc plated ( or you could paint them silver )
This from having at least 15 jacks over the years, all the black parts were black originally.
I have/had 3 California cars ( built in the Los Angeles GM plant) over the years
I actually remove the jacking mechanism from the jack post to paint it. Then replace it.
Paul