Scripts, textures and prims, oh my!

I am trying to use a menu system to allow a user to change the colors and textures of various prims within a linked group yet not effect other prims within the same group. I know this is possible as I have seen objects made by others that can do it (ie: changing colors/trim on vehicles such as wings and body being two different colors yet they are linked). I have yet to be able to figure out how to do it without changing ALL the textures or only the texture on the prim that has the script in it. Can someone please point me to a good resource that will explain how to do this?

http://secondlife.com/badgeo/wakka.php?wakka=llSetLinkColor
http://secondlife.com/badgeo/wakka.php?wakka=llSetLinkTexture