Lecra...there are so many parts to any building so this wont be easy. What you can do is assign a new lambert and change the colour...in the attributes editor. Dont forget to hit the '6' key to see textures you may have applied...if you post the file Genny will have a look by the sounds of it.
cheers bullet
bullet1968
"A Darkness at Sethanon", a book I aspire to model some of the charcters and scenes