On pg 55 of the Osborne Chassis assembly manual there is a small table thats gives the rod colors (silver, red & yellow) for the three different automatics. The C6 is shown to have a red shift rod (D0ZA-7340-B) & lock rod (D0ZE-7E330-N) I assume they are all Cad plated. If you dont have a chassis manual I will post a pic.
Also, I looked at the Ford Listing of Numerical Finishes to see if I could determine what type of finish Cadmium is and I think youre looking at S39, Cadmium plate 0.0005" (electrolytic or mechanical).