Mixed Tamiya Khaki Drab and NATO Green. Not sure quite what shade I should be going for. Comments requested.

Difficult to tell from your picture, but it looks a little too dark to me. Questions keep being asked about what colour is "right". My father was a transport officer in an artillery unit in WW2, and he told me no two of their vehicles were ever exactly the same colour. Colour depended on the batch of paint, the conditions under which it was applied and the skill of the squaddy doing the painting. So search for a "right" colour if that's your thing, but there were variations from unit to unit and from vehicle to vehicle.

Thanks, Ian. I will lighten it a bit.

Any colour you like as long as its green for a wartime vehicle. I usually use Humbrol 116 and 163. Incidentally 163 is exactly the right shade for post-war dark green and no one else makes a shade that comes remotely close.

I had been told all British vehicles were painted a specific color, after 1943. While we are on the subject, would field applied camo be an option?

On my monitor, the color is quite dark, but that doesn't necessarily reflect the actual color you used. British vehicles were painted either SCC2 Service Brown, from 1941 until early 1944, or SCC15 Olive Drab, from the spring of 1944 onward. Old vehicles were not to be repainted unless the paint had deteriorated (but lots of Regimental Sergeant Majors wanted their unit to be uniform in appearance, so most vehicles had been repainted in SCC15 by the time of the Normandy landings).

As the name suggests, SCC15 was supposed to match US No. 9 Olive Drab, and it was close, though slightly greener in tone. If I had to start with Tamiya paints, I'd probably start with Olive Drab, lightened a bit with Dark Yellow for scale effect, and possibly add a little Nato Green to skew the shade a bit towards green. Once you add a layer of general filth, the exact shade doesn't matter a whole lot.

IN NW Europe, the most common disruptive color was Tarmac, a near-black color. NATO Black would work using modern paints.

That is very helpful.

I've had success with the Vallejo Surface Primers, I used Russian Green as the base coat and misted a light coat of Olive Green. But colour is a really subjective thing, it is what YOU thin is right.

I'm using a mix of Khaki Drab and NATO Green, with a OD filter. The wash will bring a little more brown into it.