Forgot to mention that clothing tends to fade differently under different conditions (ETO compared to PTO for example).
As for color wartime photos - eh, wartime color photos that is - a lot of those are colorized afterwards.
And mostly done by studios who don't have the faintest ideas how a certain uniform looked like.
Even the real color photos are sometimes not really accurate as the technique wasn't as good as now.
I meant by looking at photos of that time the way equipment was (not) carried, how mixed the uniforms can be depending on the time period (late war), weapons carried, insignia worn or not worn, etc.
If, for example, I would re-enact a company commander, I would not have the shiny bars on my shoulder straps and white insignia on my helmet ...... don't want to re-enact sniper bait.
Unless I am re-enacting a company commander at some base in England or the USA of on parade.
Erwin