Mine is this little tidbit about Khaki’s from https://www.heddels.com/2019/05/history-khaki-anything-drab/
“Tried and tested by all the major powers, khaki-dyed, lightweight cotton twills became the de facto uniform for any colonizing power. If you were going to ship your boys abroad to pillage and conquer someplace in the Southern Hemisphere, khaki was your go-to color.”
I find this hard to believe.
https://en.m.wikipedia.org/wiki/Gum_base
They’re right.
There are petroleum free alternatives.
https://www.forestgum.de/products/minze-9er-18er-pack
But they are very small alternatives.