Sorry for the really late reply, steam doesn't automatically subscribe you to the discussion forums generated for your addons and I've only just realised that, so there are a bunch of discussion posts I have only just now realised exist.

It looks like you've turned the sunlight slider down but not the ambient light slider. The sunlight slider will get rid of most of the out-doors light, but not all of it, leaving you with a sort of dimly-lit map like you have in the screenshot. If you want it to be completely pitch black like in the screenshots you have to turn both down.