I've created a small addon, only for my mission. It's a light source whith custom brightness value, for the bigger fire effects I've placed. - You can dpbo everything if you like, it's "ZOS" on the beta mission board.
Another thing I've noticed in Mig's Friday the 13th mission is, that it is possible to play dark night missions. - We'll at least on my pc. I've to darken the room completely and set gamma to max. Then it's really possible to see (still without seeing much). A very atmospheric, realistic night.
Only looking at the map will blind you for a while and you've to use the cursor for aiming, not the iron sights. Oh, and you have to know your keyboard blindly.
If your mission really needs darkness, just tell the player all these tricks and it's possible to have fun.