Reason behind: getting day and night lighting (or stormy and clear, dusk or day) for random skydomes.

Skys work fine....shadow regions less so:
Here's what I've got: two shadow regions, each about the same size (cover most of map), one called "light" and one "dark." Each one gives 1 directional light intensity of 1 (full), the other intensity of 0 (none). The idea is I remove one (through the random bit of the lua) to get the opposite lighting effect. Problem is it isn't doing anything...both lights seem to be loading. Oh and I'm using
RemoveRegion("nameofregion")
Inside the random sky+fx function (which works).