What base color do you most use for the basic German WW2 uniform? I have heard that Dark Green or Field Gray are the most common. I am starting a new dio and I would like to get this fairly accurate. The Dio is set in Ukraine 1943 or 1944.

Field gray is the usual. Tamiya do an acrylic XF-65 I think that you can lighten or darken as you wish to account for dirt, wear and different clothing batches (it is unlikely all uniforms would be the exact same shade). I also use humbrol enamels, two colours in particular, though I can't remember the numbers now, I could get them for you tomorrow.

Hope this is of some use,

James

Field Gray (Feldgrau) was a medium gray-green shade, and is available in most model paint lines. Don't use the Model Master version, though, as it was apparently matched to a non standard officer's uniform, and isn't green at all--officers purchased their uniforms from private tailors, and had a lot of latitude in fabric color. And Gunze Sangyo calls their Dunkelgrau (the vehicle color), Field Gray, just to confuse everybody. But the Humbrol and Tamiya Feldgrau shades are reasonable.
This was the color used for temperate zone woolen uniforms. Metal uniform items like helmets and gas mask cases were painted a similar color. Buttons were white metal. In the final two years of the war, quality suffered, and wool was replaced by shoddy rayon/wool blends, which were less green.
The summer uniform was reed green cotton denim.
For accuracy, don't use one color for everything. In the real world, no two items of military clothing will ever be exactly the same shade, and no batch of field gray paint will ever exactly match a bolt of dyed field gray fabric. Start with a basic color in your mixing tray, and add a tiny amount of any other color to the mix to create a unique field gray for each garment and piece of equipment. If the troops are freshly equipped, this should be very subtle. If they have been in the field a long time, there can also be a wide variety of faded uniform colors (there were no dry cleaners on the Russian steppes, and field gray wool tended to become more dingy and yellowish in service).