That's probably not too far from how they were anyway .
Over on the GHQ forum there's some good threads on painting 6mm AFVs, some of which also show WW2 German AFVs.
Here's a thread that might help with some input from the guys that paint the GHQ models pictured in the GHQ catalogue:
link
Some good piccies on this page:
link
If you want some good references for German AFVs 'Panzer Colours' 1, 2, and 3 are pretty good but you may have problems getting a copy.
Basically upto 1942-ish they were grey and after that base colour of dark yellow with any combination of red(-ish) brown and/or green over the top.
They even applied the paint with brooms so you have free license to daub it on however you like .
And you can never put too much mud on them.
Experiment and have fun.