Paint Black Design on Hubcap

I haven't done this hubcap detail but have done fender badges and other similar parts.
With a little masking ( or none ) you could spray paint it and wipe away the excess. I use a small piece of flat synthetic dress shirt type material wet with thinner laced between my fingers so only middle finger does the wiping. I recall whittling a pop cycle stick to a point and wetting it with thinner to get at some very small detail. Forgot what part that was.
You must keep in mind that this sort of small detail wasn't absolutely perfect when the parts were brand new. Nobody looked at them close enough to notice imperfections. They might notice on the 4th or 5th time they washed their new car. Thus as good as new is doable.