The thin (about half inch wide) plastic strip insert round the beltline can have its color restored. I first did this about 40 years ago on a Bedford CA motorhome. I use a steel blade about the same width as the insert, and scrape it to remove a curled shaving of the bleached plastic as when using a wood plane. Yesterday when I did this I used the blunt end of one of those craft knives where one can break off a small section to use a fresh piece of blade. However, I used the broken edge, not the actual blade, as the broken edge was just the right width. Using this method the original color will be revealed. On my 1988 Excella I did this in 2000 and now again in 2008. Next time I will invest in new insert, as the plastic will get too thin. It's not always convenient to obtain the insert, or to pay for it, or to risk water ingress by drilling out rivets, so an hour of careful scraping is an alternative.
Nick Crowhurst, Excella 25 1988, Dodge Ram 2500 Cummins Diesel. England in summer, USA in winter.
"The price of freedom is eternal maintenance."