Just run across this wee pic of a selection of authentic field grey German army uniforms, thought it'd be useful for anyone going for "historical accuracy"
Yup, plus as the war went on materials and production sites and availability of dye would've changed. I was reading a while back about the traditional British "redcoats" and all the interesting colours that would go after time. Any extended campaign would've been fought by pinkcoats eventually.
What color is fieldgrey is asking the same as what is the color of confedarate grey.
Answer......what color green is grass.
As always, just as in the case of fieldgrey. The answer is in the middle.