They are indeed "white walls" but these walls also have a lot of convexities and emarginations in them.
Yeah, the way that textures are laid out by the game engine makes that hard to emulate. I made a new texture since these pics were posted that does a better job though.
I don't have deep knowledge about the technical issues so you might forgive me and remember that I actually try to help you improving the mod and do not try to offend you or to denigrate your work.
We haven't taken your comments negatively. It's just that sometimes the technical issues make what seems like reasonable suggestions into things that just can't be done (as far as we know at this point).
EDIT: New Glaciers: