Hi Jimmy,
Yes, the rings should be black, the trusses can be left as is, they don't affect the light path.
About painting, DON'T. I tried it using all the proper techniques and still the paint chipped with use.
Have the rings powder coated matte black, it only cost me $40, no muss, no fuss, and after 4 months of use still not a scratch. Here is a picture of the rear cell.
Just look up Powder Coaters in your local yellow pages or the internet.
