Camo
Camouflage is perhaps something you don’t think of evolving drastically, yet here we are. The original camo was very literal- and included brush, nets, and other items that a person could wear in order to more fully blend in with their environment.
While humans have used a form of camo for thousands of years as they hunted, modern camo as we know it became more prolific during WWI. Today, instead of covering oneself in nets and brush, camouflage is part of the uniform and faces are painted. That certainly makes it easier to move around and use a weapon more accurately.