Humbrol Revell Paints Conversion

How accurate are paint references on instruction sheets?

Hi all,very new to this hobby but have made the change from fantasy figure painting to these strange looking beasts with guns on!! My problem is that the Revell instructions for the M4A3 Sherman say the main overall colour for the body is Olive Grey matt 66 but on looking at ref' photos the paint work is an olive greeny colour .Is this the actual name for the colour used in the period these vehicles were built or is the the name misleading?? Thanks for any help sent this noobs way!! I'm not an armour modeller but I can tell you one thing about all U.S.Olive Drab paints. They were remarkably inconsistent! They may have matched the relevant standard at the factory but the formulae varied and the paints weathered and faded in a bewildering variety of ways. Look at a decent period colour photo of a line up of vehicles or aircraft and this is usually evident. Now you'd think that was it but no,the original O.D.41 was a mixture of seven different pigments which was fine in peace time. When WWII came along it didn't need Einstein to discover that an awful lot of Olive Drab paint was going to be needed. Manufacturers set about simplifying their formulae. As a result different manufacturers used different formulae,some used as few as two pigments. The problem was the different paints weathered very differently.Pilots of the 14th Fighter Group operating Lightnings in North Africa reported that under African sun their early-model P-38s turned,rather disconcertingly,into a bright purple colour! This obviously wouldn't do. So,in March 1943 yet another standard was set, ANA 613. This standardised Olive Drab to the Army standard which had developed,despite being officially the same,into a lighter shade than the OD 41 used by the USAAF. Now you say everyone will be using the same paint. I'm afraid not. The Army did indeed use the new standard ANA 613 (which was the same as their interpretation of OD 41 anyway) but the Air Force showed no interest in it and most aircraft manufacturers continued matching to the earlier,darker,OD 41. OMG,what have i got myself into?? Addictive trying to find perfection tho isn,t it? My next question is....how to work out fading of the colours used.Any good weathering manuals out there that will satisfy my general ignorance? Gone the full hog and ordered a compressor and airbrush as well!!!!! Forgot to thank everyone for info...Cheers guys! @stona I see your a birmingham lad aswell ,know Rednal at all? OMG,what have i got myself into?

Airbrushing and Finishing Scale Models

Modelling the F-4 Phantom II