Just picked up my grills today from the body shop. I had them painted gloss black and they look great!
The shop did a perfect job sanding them; using a special primer for chrome & plastic and spraying them with a paint designed to bond to chrome. They took the grills apart (since the chrome surround snaps off) and put them back together after spraying.
I have not installed them on my vehicle just yet as it is still snowing out, but have them ready as soon as spring comes around...if ever.
Painting was approx $175. Here are a couple of pics as promised.