http://thenokiablog.com/2007/03/27/easy-to-replace-the-nokia-n95-cover/

seems the back cover is easy to change
which is good news as me and my wife have the same ones.
and i want one plum one sand.

but replacements aren't in the retailers yet - well they will only ever been service replacement parts, not retail as such i know datakits stocks
alot of them. and its not long before ebay will be full of them!