I use Tamiya XF-61 Dark Green with just a touch of white to lighten it a bit.
Used the wash followed by drybrush technique. I used rustall in the corners to simulate the "Rust/Dirt". Then used Tamiya Earth darkened with flat black to blend it all together.
This was out of the box with no additional aftermarket items.
The tracks are Link and Length plastic. The biggest headache was to fill all the ejector pin holes on the track pieces
Tom