Changing Web Clip Icons with Winterboard?

[wewtaco]

I'm fairly new to making themes with Winterboard, but I understand most of it. I can't figure out, though, how to change the icons if web apps permanently. Whenever I change an icon in /private/var/mobile/Library/WebClips, it changes back as soon as I press it. The only way I could think of to permanently change an icon is to do it with Winterboard, but I don't know how to do that. Is there a way to theme web clip icons via Winterboard?