TL:DR: If your clothing matches the immediate environment around you, Zombies would be much less likely to detect you on sight.
A realtime camo system, based on the clothing of a player and the environment around him would allow the players to interact more with the map itself.
Each clothing piece would have a value (refered as “Camo index”) connected to their color, and so would every surface. The game would make an average of the color values (with the more major clothing pieces being more important) and would compare it to the values of the materials the player is near. The higher the player’s index is, the more “invisible” he is, game-wise.
This could be used as a system for how zombies detect players, where unlike in 3.0 where they were either omnipotent or downright blind, the whole system would require a bit of skill.
For example, a player wearing all green clothes, but not a ghillie suit, on a green hill could have an index of 90%, thus having a 90% chance of not being detected by a zombie, whereas somebody wearing pink would only have a 10% change of being ignored.
This system could also be used for others things, such as working against the Bandit NPCs on the Trello (speculation, not confirmed to be hostile), could work against sentries, etc.