Silver and Black Caboose Roofs

I think the silver roof on 04343 was something done in the very last years. I believe 0589 was given the silver roof treatment as well-also in the last few years. I have photos of both taken in about 1967 or 68 with the silver roofs. I suspect it was paint over the existing black roof. I believe the roofs were covered with some sort of tacked-on tar paper and then "painted" with some sort of tar roofing substance (someone with more knowledge on the subject can tell us exactly, I would think). It was a sort of "grimy black" in color, as has been mentioned. Except for 04343 and 0589 (and possibly other Alamosa cabooses) in the last few years, the roofs were generally the "grimy black" on D&RGW cabooses.