welcome to the forum. I did a light sand to rough up the surface, gray primer, then flat black.. if you want it to have a shine, gloss black.

 

Performix Plasti Dip is a rubber like spray can product I have used on grilles, wheels, window trim, etc. I has proven extremely durable and has lasted several years so far with no problems. It is a has a flat black appearance. Preperation, ever over chrome is to simply make sure the surface is really clean. It is also available in other colors. You can find it at most auto supply stores and the usual large home repair stores.