Here are some screen-grabs of work I did for Zero Latency VR. Models were made by James Brady. Bakes and a paint-over from zbrush, along with the models were supplied to me, so I could texture the assets with Substance Designer.
On the substances:
All of them have adjustable parameters. For the bodies there are parameters for age (affects dryness, cracks and colour of the skin. So fresh zombies and more decayed zombies can be randomised if needed).
There are parameters for dirt, old dried blood, blood splatter, cavity blood, blood dips from eyes ears and nose (the length of those).
There are separate parameters for the eyes, so you can have fresh eyes, bloodshot eyes, and even dried out, almost opaque eyes. And a hue, saturation and brightness parameter for the iris.
For the teeth there are parameters for colour as well. And parameters for dirtiness and bloodiness.
The clothes and shoes have parameters for dust, dirt, mud, splatter and colours. (Some items have more then 1 colour, for instance the sneakers. The colours can be adjusted independently for those, with parameters for each colour.)