The animated fog
Almost like any other thing within Unreal Engine, you can do some animations for it. Some parts of the engine are super-responsive to the animation system, while other parts have a limited access. But speaking of the fog, it has a limited access in order to animate some values. You can use different ways and methods to animate values at runtime or even during the Edit mode.
Color
Height fog color can be changed at runtime using Linear Color Property Track in Matinee. We are going to dive deep inside Matinee in the next chapter, but here is the recipe in advance!
By following the given steps, you could change height fog color in-game:
Create a new Matinee actor.
Open the newly created actor within Matinee Editor.
Create a height fog actor.
Create a group in Matinee.
Attach the Height Fog actor from the scene into the group created in the previous step.
Create a linear color property track within the group.
Choose the Fog Inscattering Color or Directional Inscattering Color option to...