Setting default toolbox textures?

[Konstant]

I'm trying to figure out how to set the default textures of buttons at render time.

<Property name="NormalTexture" displayName="Normal Texture" type="wowuides.Texture" value="@skin@" visible="true" category="Appearance" defaultCopy="true" />

It has something to do with this.

Or... Do I need to build my own xml frames and inherit from them?