You can download the Master Skinnerz Pro Kits (they're in photoshop format ".psd" but you can open and edit them using GIMP if you dont have PS) http://www.barkingpig.org/msz/pages/kits.php
Its a got a wireframe to guide to you to make your skin (so you dont need the default shadow'd skin)
Not sure if this is what you mean though...
If you just want a plain white skin, just save a full-white image.