I am started playing Glest at this weekend. It is wonderful game, but with very, very dark nights. Even turning my monitor to the maximal brightness did not help me. Then I tweak .xml a bit to make brighter nights.
In the /glest/tilesets/forest directory, open forest.xml with text editor.
Search for <moon-light and increase numbers for colors (greater number=brighter). Save.
You can also edit other tilesets in this manner.
After this game became more interesting for me. (because I can now see what happening at night not only hear!)