Headed out to the garage to take a look see. I'm in the process of disassembling the bed and running boards for repair/paint and replacing the wood. My truck has the RPO side spare tire and I removed it from the bed and disassembled it and put it in the glass bead cabinet. So the repaint color was yellow, under that was a gray primer under the gray primer was a heavy coat or multiple coats of the factory original coopertone color under that was a thin black primer. Rear fenders are factory coppertone too. So at least on the 53 with RPO side spare it seems it was painted with the box as a unit. BTW yesterday I glass beaded the splash aprons and they were the same.
Now one could venture a guess that dealer installed side mounted spare tires could be different especially long boxes the don't need a rear fender change. I'd venture a guess that they might be found semi black in color, just a guess. Dealer installed short boxes would need the rear fender too so the dealer would probably repaint to body color.
Steve

Last edited by sstock; 02/24/2014 9:21 PM.
1953 Chevrolet 3100
261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done
In the DITY Gallery
Video of the 261 running

1964 GMC 1000
305 Big Block V6, sm420, the next cab off restoration