I'm not sure about the Tamiya figures, but the Dragon Tank Riders are late war and wear M1943 jackets. I use Vallejo 893 US Dark Green for the base, 886 Green Gray for highlights, and 979 Camo Dark Green for shadows. For webbing I use 998 Khaki as the base, 819 Iraqui Sand for highlights, and 872 Chocolate Brown for shadows. I use shades of brown for the boots. Steel helmet I use either 889 Olive Drab or Tamiya xf-62 Olive Green. Oh and buttons on the webbing are 889 OD. Hope this helps!
Also, Pants are either shades of dark green or 873 Field Drab with Iraqui sand for highlights and Chocolate brown for shadows. As a general rule of thumb, if the pants have cargo pockets, paint them OD.