I recently started a question where I wanted to know how to run the most minimal Linux desktop (Use gnu-screen and X instead of desktop environment?). And the conclusion was that I would need a window manager which would handle all the different windows and switching between them. Since using screen and X was not enough.
The closest thing I could find to have different windows/screens and only have the gui of the application running was ratpoison. It reminds me alot of the workflow of using screen to have multiple instances to switch between. Also it could do window splitting which could be convenient.
The only thing I see as a downside is the look of the gui of the applications which uses an gui. For example if I launch firefox, it uses some kind of default window chrome and icons.
What I want to know is how do I change this to use other icons and window chrome? Is it done via X or ratpoison? Or is there anywhere else I can change this?