I painted mine with a bright white spray paint that is rated for plastics. I bought it at Home Depot (it seems like a lot of new paints are good for plastics). It is a bit of work taping and adding newspapers around the areas that are to be painted but they look brand new again. I did this 2 years ago and they still look great.
2013 Ram 3500 Megacab DRW Laramie 4x4, 6.7L Cummins, G56, 3.73, Maximum Steel, black lthr, B&W RVK3670 hitch, Retrax, Linex, and a bunch of options incl. cargo camera
2008 Corsair Excella Platinum 34.5 CKTS fifth wheel with winter package & disc brakes