Dead Rag

Bright orange, pink or another high-visibility colour is standard so it's unmistakable at a glance even at a distance or in dense cover, letting other players immediately know not to engage someone who's already hit and walking to respawn.

Most fields require carrying one as basic kit alongside eye protection, since a hit player without a visible marker can easily be shot again by accident, wasting the shooter's ammo and causing exactly the kind of dispute hit rules are meant to avoid. It's a small, cheap item that solves a real, common problem on a busy field.

Choosing a colour genuinely different from the field's natural surroundings and from any team's uniform is worth thinking about, since a rag that blends into green foliage or a green-toned uniform defeats its own purpose.