My favourite base colour for early-war German vehicles is VMC 869 Basalt Grey. It's substantially lighter than their German Grey; it darkens slightly when the weathering washes go on, but still not nearly that dark.
(https://3.bp.blogspot.com/-qq624CJzmFY/WTngyWjX5yI/AAAAAAAAIQA/g6kIngF0pjMridw7It0K9Ja3oFUj7htZACLcB/s1600/20170609Pz3F.jpg)
For the Brits, I use Mike Starmer's recipe for Khaki Green No.3 and VMC 888 Olive Grey.
(http://4.bp.blogspot.com/-AH1cO0ZGGQA/VpBQHX5xBnI/AAAAAAAAFks/KLvObWxBUDY/s1600/kg3.jpg)
That recipe is right here (http://mojobob.blogspot.com/2016/01/khaki-green-3.html).