I have a theme which I'd like to edit so the colours match my wallpaper better. I've downloaded carbide.ui, but I can't find a way to edit the .sis file to change the colours. I assume I need to extract the sis file first, bit I can't get Nokia's unsis working. Is there another way of doing it?
Editing themes
Ask the original theme developer to send/give you the original theme files.
Or, ask the original theme developer to create a new version of the theme to match your wallpaper.