Hey Zach, great to read you

.
The graphic used for fog of war is somewhat hidden and badly named (by silly me), you find it under Default/New Module/ui. The name is offScreenBlack.png.
You can overrde its usage by placing a file of the same name (offScreenBlak.png) inside your own module's ui folder.
You can also customize the opacity degree for fog of war under module properties in the toolset - look for fogOfWarOpacity property.
The fog of war interacts with the dark&light system, it might look strange when using something else than black for fog of war, but I have not experimented with this so far. Same goes for the way the fog of war fades out slowly - I did only test it with a black fog of war.