Wait for someone to replace one with an aftermarket off road bumper and buy it from the classifieds, or buy a new one from eBay or dealership and send it to the paint shop.
I had a chrome bumper that had some rust on it and wanted it painted. I had to take it to a place that chemically stripped the chromium and nickel from the bumper. I didn't have any problems with paint sticking to it.
You should be able to order Lariat Sport or Platinum caps that are primed and have them painted.
I am waiting for the Tremor caps (shown) to become available so I can install the Borla Touring exhaust on a Platinum.