My 97 zj had a faded repalacement bumper that didn't match the rest of the tupperware. I found a web site with the fix. http://www.urethanesupply.com
had a product called Bumper & Cladding Coat. I bought a spray can and coated the bumper. The color is color matched to the year of the car. There are many different grays used!! The result was perfect. The texture color and sheen were great. I would guess that they have a match for your car.