I'm doing some work on a 1965 HY pompier ambulance. Does anyone know whether the French fire department vehicles were always painted in a particular shade of red or whether it varied with area and era ?

That's easy Rouge Pompiers was an official Citroen color (AC 445) but you don't know if they did put it on your HY.
Why? Here a story about a friend of mine he was a fireman in france. Their unit needed a van so they did go to a scrapyard and bought an old Renault Estafette. Complete with a 50cm hole rotted in the side. They pop-rivetted a plate on it, paint it red and ready was the fireservice van...

Thanks AZL
True but at least now I can try AC445 and see.