While I havent looked at the files my self (I'll do that when I get some free time to) Some things you guys may look at is that the texture files might have two images overlayed instead of just one image. Seeing as how alot of KOTOR textures seem to have a Bump map to them to give them there glossy and bumpy feel (or does it just appear to look that way?) If thats the case then it would be safe to assume that with each texture you might find some kind of bump map or shadeing map along with it.
With any luck we will figure it out. Allmost anything can be edited. Ultima Online is proof that with work any file format can be cracked and edited.