There is no need in any of those materials, or UNLIT flags.
Go throw this steps carefully (TESTED):
* in WED, go to: File->Map Properties->Sun
* set all three Sun values to 0 (if you'll need to have some shadows, from the moon let's say, then increase it)
* set all three Ambient values, to something around 10-30 (depends on your needs, tweak this in future)
* set 'sun_light' to 0 (this is the thing, that affects on models, throw the walls, thats why they are shinning a bit)
It's tested and it works. If it doesn't work for you, then you've made something wrong.
Greets
