I just got pictures of the new awing from my RV dealer. The awnings are black and dark grey strips on top, white on the bottom. I wrote him a long email regarding black and problems associated with black and he forwarded it to the Jayco rep, the Jayco rep forwarded it to the factory. I will let you know if I get a response.
Doing some research on propane, the NFPA (National Fire Protection Agency) requires all propane tanks be painted in a heat reflecting color. I doubt they would think enclosing a tank, or two tanks, in a black cover would be prudent. Temperatures in vehicles typically can hit 150 degrees inside within minutes. I would dare say 150 to 175 inside the dark covers would not be unusual.
Sometimes designers choose items for esthetic rather than practical purposes. This is where engineers, specification folks need to step in and "assist" them in making appropriate choices, I have done it 100's of times for products I represented.
I hope they see the potential for liability and at least offer choices...
2011 Toyota Tundra double cab