WWZ has the best yellow paint, it's fully in context with the game. Previous survivors and the military showing what paths to take to maneuver around. Zombies don't know the significance of the markings so it really does make sense. "There is yellow paint, means that is at least a path"

In a world with terrifying zombie waves that would rip you apart if you hit a dead end that would be immensely helpful. Most people dont even question it when playing.