Glossy Deep Bronze Green was used for many years as a standard colour for vehicles in the British Army. During the years of National Service, up to the mid sixties, the equipment was usually kept very clean and highly polished, with soft skin ‘B’ vehicles often inspected by Officers in white gloves! I understand that these inspections even included under the bonnet.
In the U.K. and Europe, a camouflage of green and black (NATO green and NATO black) began to be applied in the late sixties / early seventies. The U.K. manufactured vehicles still entered service in overall Bronze Green but had to have the cammo applied at unit level when required, either by brush or a spay gun if available. This practice continued until at least the nineteen eighties.
Vehicles that had undergone a base overall (rebuild) were re-issued to units painted in overall NATO green so just needed a coat of black if required.
I never noticed a significant variation in shade of the NATO green if it was applied properly, but sometimes the matt paint would dry satin or even gloss if the tin wasn’t stirred well enough. Also, the paint wasn’t a particular good quality so soon became darkened by dirt and oil. This was particularly noticeable on the engine decks of AFV’s, especially tanks, when the black and green sometimes became almost indistinguishable.
The only real difference in the shade of matt green was in Northern Ireland, were protected vehicles such as Snatch Land Rovers, Humber Pigs, and Saracens were often painted overall in a slightly darker shade. This may have been to distinguish Internal Security vehicles from dedicated combat types for political reasons.
The camouflaging of vehicles at unit level wasn’t always consistent. New and re-built equipment would sometimes slip through the net and stay unpainted for months or even a year or two, particularly soft skins. On camouflaged vehicles the cab and rear cargo area of vehicles such as Land Rovers and Bedfords would also often remain in Bronze Green until they became shabby. This was especially true of cabs, which would often stay in their original colour for several years until eventually given a coat of NATO green. Externally, once a vehicle had been camouflaged it was often regularly re-painted, this depended on how obsessed the unit was with bullshine!
Although vehicles were painted matt green and black, new replacement parts were still issued in Bronze Green so it wasn’t unusual, for instance, to see an AFV in cammo with glossy new stowage bin or mudguard.
This information is correct as far as I can remember, although inevitably there would have been some exceptions.
From a modelling point of view, I find that cockpit green (Humbrol 78) darkened slightly with some Humbrol 30 green gives a good approximation for NATO green.
I’m not sure if NATO green has changed since back in the day. It doesn’t seem to have done judging by pictures, but I admit I haven’t seen many vehicles in close up lately apart from the occasional Territorials. It seems to be standard now that new vehicles are issued in a NATO green colour. One reason for a difference in shade could be that that the manufacturers finish is not quite the same as the issued paint.