How to paint repop 1971 rallye dash lens caps?

I will have to paint the center "cap" section on some new repop rallye dash lenses - I practiced on the old ones using a brush/paint and it looks like crap.
Anyone have experience doing this before or a certain method? I have a chrome paint pen for the outer ring, just looking for a method to paint the centers.
Below are the old ones I was practicing on.

Thank you!

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