The feldgrau used in M.1907/10 unifrom items is NOT the greenish colour that WWII stuff was made. It is a more light heather gray colour. The only ones who have reproed this colour wool were Great War Militaria, back in the day. Some later uniforms were made of the greener stuff. Actually, if you want to know, feldgrau was a shade that was all over the place and covered many hues.
Most stitch-nazis don't understand just how UN-uniform the German wool colours were. There was NO ONE feldgrau colour. Learn this fact and stop insisting that all stuff be a certain shade of colour and you wil be on your way to a better portrayal of the Frontsoldat.
From left to right: A M.1907/10 Feldrock, a 1914 "Transitional" and two M.1915 "Die Bluse". We clearly see the different shades of "feldgrau" cloth, ranging from light gray to pale green The M.15 Bluse on the far right, compared to the one just below it, even is a different shade of graugrün. This photo clearly illustrates the variations of colors of that is all, called "feldgrau". This is most likely due to poor dye control in production and the fac tthat dyes then were not really colour-fast.
(picture and caption from Militaria Magazine)