Ya, I've been wondering about this as well... I have some German armour in the stash and will face the same decision point.

There is some discussion related to how early in the war we are talking about, that they may have shipped that way early on, just to be painted over in the field by crews who wanted to avoid a big bullseye on the side of their tank...

One commentator even made the sarcastic observation that every rule was followed, until it wasn't.

The interwebs mostly seem to agree with [USER=22167]@Jakko[/USER] , but also point out the inevitable exceptions with photographic evidence.

I did find this interesting site, though I am not knowledgeable enough to attest to their reliability:

https://panzerworld.com/german-armor-camouflage

with two example photos of Pz-III: one with, one without turret hatch painted same as exterior.

[ATTACH=full]133618[/ATTACH]  [ATTACH=full]133619[/ATTACH]

Go figure!