Here is a tbl I made for Shells to look like Dragon flights, mythrils, armor of trials, rons set.
http://www.megaupload.com/?d=MXODNREB
Make a backup of your current item_org.tbl just incase you want to switch back
Edit
Ok here is one to make both Chitin and Shells to look like the gold shells
http://www.megaupload.com/?d=C6D5V6EZ
Remember this is only client side so only you can see it.
Credits go to IceMan(good friend of mine)