This is why soldiers wear unit patches

What is left out of the story is that they were also developed from Civil War Corps Badges. There is even another legacy that follows on from that; in infantry battalion nicknames that the first battalion is the Red battalion, the second battalion is the White Battalion, the third battalion is the Blue battalion, and the fourth battalion is the Gold (Yellow) battalion. You would also note that in some units that have additional battalions that they will then usually follow with the Green battalion and then other colors.

US Military Heraldry is a fascinating subject.

Interesting, thanks for the post.

i've never traded patches to anyone