Thanks for the fast reply. 
I modified Bismark in 3ds Max, then I exported the modified Bismark and merged just the new head model into the default Bismark nif, so it should be already using the default lights.
It must be something different in my case.
Leaderhead creation has to be one of the most difficult aspects of modding civ. 
I'm going to try a few different things to see if I can fix it like removing bismark's lights merging other leader's lights into the scene. Something has to work...

I modified Bismark in 3ds Max, then I exported the modified Bismark and merged just the new head model into the default Bismark nif, so it should be already using the default lights.
It must be something different in my case.


I'm going to try a few different things to see if I can fix it like removing bismark's lights merging other leader's lights into the scene. Something has to work...