Generally vehicles produced before than would have had a panzer grey base coat. After that the vehicles had Dunkelgelb base coats. The camo patterns were applied in the field, by the crews themselves and coud vary greatly depending on what paints they had and artistic liscence. Many of the Pz IIIJs were upgrades, they had been damaged and when they were repaired they were routinely up gunned. I'm not sure if they were given new basecoats at that time (I suspect not).
Depending on what front you are doing, a number of units were transfered from Africa or had been destined for Africa and rerouted to the east. They would have arrived in a sand color and camo, time permiting, would have been added afterwards.
I generally try to keep that patterns similar within units. It just makes things easier.
As far as the Russians are concerned. Most were dark green with whitewash in the winter. They generally didn't have unit markings. I think there were more camo patterns in the early war than in the crunch time of 43--though I have seen photos of guard units with camo patterns. This might be the exception that proves the rule: they were unusual enough to make their way into books.
An interesting note that if you research German sources you will fnd that the tank crews themselves often did the "Camo". They were issued paint in varying quanties in buckets and mops. They would use the mops as "paint brushes" and I had even read sometimes they sometimes just threw the paint on the tanks with the bucket. The object was simply to break up the lines to make the vehicle harder to spot.
Another interesting note about camo is that there exists german equipment captured during the Bulge that was still Afrika Korps sand colored! If you go to Europe to the region of the Ardennes you can see the equipment on display at vaious locations. That shows you that sometimes the paint scheme was never altered.
Panzer Grey didn't die a sudden death. It was very slow & confused.
A recently document dating to mid 1942 ordered all factory fresh vehicles to be painted in dunkelgelb. This order obviously wasn't carried out to the letter, because Panzer colors in 1942 varied wildly. However, Stugs photographed in Stalingrad were indeed in dunkelgelb, so some AFV's obviously got it. My bet is that the IVF2's had grey in 1942, while the later IVG's probably arrived in dunkelgelb, even before 1943. Same goes for the IIIJ vs. IIIL.
Back to 1942. The whole RAL spectrum was used in 1942 Russia. Most likely the AG North & Center units (on the defense) stayed in Grey if for nothing more than lack of new paint. Everything went south that year.
For AG South, your panzers can be painted just about any combination of Grey, 4 DAK colors, RAL brown, RAL green. Any camo pattern you can think of. That would include grey tanks that survived the winter of 41-42, new vehicles arriving early in 42 which the crews painted over the grey with other colors, etc. You can't make a mistake in 1942 Russia.
Big exception: the early Tiger battalions (503, 505), were in grey late in 42 going into whitewash in 43.
By the end of '42, mostly all AFV's were arriving to the front with factory applied dunkelgelb, which was quickly whitewashed for the '43 Kharkov counterattack.
In '43, yellow was everywhere, but some Tigers (ex. Das Reich @ Kursk) were still in grey even in the summer.
I just read your earlier post & it seems that you are looking for scenario advice. All of the tanks you mention could fit into a late 1942 battle to relieve the Stalingrad pocket.
You could have a weakened P.D. that has been on the line for some time, containing IIIJ/L & IVF2, fighting to maintain the line, then the 503 Tiger Bn. comes in with the early Tigers & IIIN's (in grey) for a counterattack.
Your Sov's could have the T-34 & KV1-s.
G: 83, 28, 64, 22, 6, 23, 112
R: 20, 1, 17, 18, 26,
You could even have the Sov's overrunning a German airfield with the Germans counterattacking.
Sovs would be base mid olive green, camo some with dark brown.
