Painting German vehicles in Dunkelgelb has always been a bug-bear for me. I much prefer a nice easy coat of panxer grey... far easier to do!
But after a few years experimenting I think I may have finally cracked it!
For this method you will require some of the Games Workshop foundation paints, but they are worth it, especially for WW2 gamers.
STAGE 1
First give the models a heavy drybrush (What I call a 'Wet-Brush') of Citadel Foundation paint 'Charadon Granite'. This takes away the harsh black undercoat and is in effect your undercoat for the dunkelgelb. It may seem pointless to do this with later steps but this colour gives the others a depth and provides shading that isnt black on the final model.
This colour also provides a perfect undercoat for German uniforms so do a few of your infantry while you are at it!
STAGE 2
Next apply a heavy drybrush of Citadel Foundation paint 'Khemri Brown'. This is your base colour for the Dunkelgelb. Dont worry if you go in gaps or areas that should be shaded as this can be solved later when black lining any details.
STAGE 3
Next apply a heavy drybrush of Vallejo German Cam. Orange (824). This is effectively the main colour on the vehicle.
STAGE 4
Now add some Vallejo Buff (976) to the Camo Orange and drybrush this over the previous colour. This is the first highlight for the vehicle.
STAGE 5
Finally add more Buff (around a 50-50 mix) and lightly drybrush the whole model. This gives the final highlight and you should now have a reasonable representation of German Dunkelgelb.
After this add further details such as; paint chips, black ink lining, stowage and so on. I also always gives models a very light drybrush with an off-white or dust to give them a weathered look and to blend the differeing colours together.
Hope this proves useful to someone!