Him Sherlock 82.
I wouldn't worry too much about the really correct colours and shades unless you're going to model a pristine one right off the production line, and even then they varied. As Ratch and Ntrocket 88 said the base colour was a dull dirty sandy yellow but in late 1943 or early 44 the yellow was unobtainable and many factories reverted to a dark grey or the tanks even left the factory in a red oxide primer. Also the crews were supposed to camouflage their tanks with supplied green and brown paint. some crews did in a myriad of different patterns some only used the green or the brown paint depending on the time available before they were needed at the front. These greens and browns also varied from dark green (RLM 71) to a light olive green, the browns were more standard being a very reddish brown but had variations due to the solvents used (usually petrol) in shade.
A very good paint for German armour is Vallejo and the do colour sets for the various German schemes complete with instructions on how to get the best results with shading and blending. You might like to try a winter scheme as this covers all kinds of evils, and it’s easy and looks great. Just do a basic camouflage without being to fussy with colour and shade then roughly brush white over the whole thing with a semi dry stiff-ish brush. I’ve done several winter schemes and they look great, unfortunately I can’t show them here as the builds are not Airfix.
Hope this helps, but do check out the Vallejo acrylic range if you can find them you won’t be disappointed. Looking forward too seeing the results.
Remember we do this for fun John the Pom