I imagine that post apocalypse (no matter how it comes about nuclear war, zombies, emp pulse, etc.) that all the clothing is a bit more worn, comes in sturdier materials like leather, or made from bits and pieces of fabric found by the survivors. The few luxury items left are highly valuable for those who wish to trade in real life for fantasy. But almost everyone wears more practical clothing down to the last thread. Harnesses are common accessories, useful for attaching weapons or other items. It's a very bleak place, so there isn't a lot of brightly coloured clothing. Blacks, browns, greys, tans, and white are the norm.