It was a powdered aluminum "silver" paint, applied over a powdered red iron oxide primer.
Powdered aluminum+powdered iron oxide=Thermite
I used to watch the “Mythbusters” before they went totally leftist with BHO, and they tried to recreate the Hindenburg, scaled quite a bit down, so maybe that epi’s available online.
FWIW, H2 would be rapidly escaping upwards, so only the crew in between the bladders would be nailed by the heat and flames initially...until it crashed to the ground, and the diesel fuel ignited, and the burning skin, bladders, and frame came raining down.
I believe some of the people tried jumping as well from about 50 feet. Not necessarily a smart move with the burning wreck that was following them down.
From what I remember about one documentary, one young junior crewman rode down in the tail section, and was able to cut or punch a hole in the skin between framework big enough to allow escape.
[ Powdered aluminum+powdered iron oxide=Thermite ]
Dang, that is rather scary.