Richard Townsend writes:

"I wonder if our glorious leader would be willing to describe how he did (i.e. colored) the roofs on the Swift reefers."

Well, I haven't seen a glorious leader lately but I will note that I said back in November:

"In fact, the presented information has convinced me that the
original roof color [ wood car ] was some variation of reddish brown. It now
seems more likely to me that the blackish color is a result of some
weathering effects although it COULD be that a blackish covering of some
type was applied before a final reddish color of paint. The replacement
boards appear tobe reddish brown."

Given that, I used Polyscale Tarnished Black to partly cover the roof. I then added Polyscale Box Car Red to partly cover the black. I then painted individual boards with Box Car Red and then other boards with the Tarnished Black. That seemed to deliver something fairly similar to what I see in the photos.

Mike Brock...it helps to consume some of Bruce Smith's brew before doing the painting and, yes, all "weathering was done with a hand brush.