Military uniforms are generally designed to draw attention to the wearer by their colors, fit, and decorations. On the battlefield, drawing peacock-like attention to yourself will get you killed.
This is bad.
The idea of troops concealing themselves is nothing new, one may recall 300 Greek Hoplites concealing themselves inside a wooden horse that broke the siege of Troy in1250 BCE, but like the saying that tracers work both ways in directing fire on a target while also pointing to who is doing all the shooting, camouflage not only conceals you from the enemy but also from friendlies as well.
From Nature to Hot Zone
If there’s anyone that we should credit the camouflage principle, it should be no other than earth. From chameleons to leaf-tailed geckos to leafy seadragons, the animals evolved to adapt from the (sometimes) harsh life in the animal kingdom and get away from being another creature’s meal.