I've painted numerous chrome surrounds, I recently sold a matt black set I did on eBay for £50 after buying it for £17
![Laughing :lol:](./images/smilies/laughing.gif)
I have a bit of a grille fetish, at one point I had an all black set, an all silver set and a std chrome/titanium set.
To paint the surround, I would sand it down with a rough sand paper first to really get as much shine off as possible, then smooth with wet and dry. After, it'll look like a brushed aluminium effect. Give it a good wash with hot soapy water. Then apply a really good helping of plastic primer - a good few coats. The stuff dries quick and levels itself nicely (unless you do too thick a coat so be warned) giving a smooth surface for painting on. Then just paint as normal.
I found an aluminum paint was a good match for the texture of the pre facelift titanium slats believe it or not. It also matched my silver car well but as it's a non lacquered finish was a kind of matt look. It looked pretty cool against the car.