let’s start at the beginning
What makes Project Zomboid interesting is without a doubt, the game’s own health system, more than the gameplay in general, in that it is another zombie game, but also different, with the aforementioned, Project Zomboid Unlike other games of the genre, it forces you to avoid contact with the zombies as much as possible, the “magic” of the game is in it.(However, if you don’t want to spend several months scripting just a similar health system, I don’t recommend Project Zombied as a reference.)
On the other hand, Apocalypse rising and unturned should be the objective games that give you the general idea of the game itself (to make it simpler), if it is true that those fog effects and the generic low saturation color palette in almost 80 % of zombie or survival horror games, serve to set the scene and do a great favor to many places in the game world itself
Unturned deviates from this rule and with a much more colorful palette, it still gives you exactly the same experience and at the same time gets rid of that depressive style, which unconsciously makes most players bored due to the “lack of life in the environment”. ", this in the end tires, to avoid this you could try to alternate with that colorful palette along with a day and night cycle in which that foggy effect is added at night along with less lighting and this gives your eyes a rest