I am not a WB skinner but I have changed the actual files in WB skins to suit my purposes. You need a graphics program that can deal with TGA files though. I don't know how much you know but here goes: The WB themselves are in Windows (C), Users, Public, Public Documents, Stardock, Windowblinds. I usually make a copy first so the original isn't touched. The copy will be in there. I make a copy by calling the original up in Skin Studio. Go to file, Save As. Wait a little bit then your copy will be in the Winowblinds folder with the name you gave it. You can fiddle with it as much as you want and not ruin the original.
Here's an example: Sometimes I want a solid color start panel so I I find the original files and play around until I get what I want. Sometimes I want to change the taskbar. Here's some examples:
Beist by 2 of 3
Fader by Lightstar
Aventine by 2 of 3
Black by tehZero (This one required a lot more work in total to try and get it to function like a contemporary skin. It was a XP skin only)
For a taskbar here is Essence by Lightstar, I wanted a solid dark taskbar.
So it goes without saying that these changes are fine as long as they are for your own use. Sharing these modified skins in public is a no no.
I don't know if any of this is helpful or not. I hope so.