I'm not absolutely sure this matches your requirements, but I wrote a plugin to allow me to make bulk changes to textures when I needed to evaluate quite a few options for a renovation.

http://www.sweethome3d.com/support/forum/viewthread_thread,8609#39160

I wrote a similar plugin for colours:

http://www.sweethome3d.com/support/forum/viewthread_thread,6417#28716