"Official" Dark Mode for Git GUI

[bariod]

This is a copy of the exact (still open) issue from the old repository: prati0100/git-gui#64
The comments of said issue also contain some tweaks to achieve an unofficial dark mode.

Description

Is there dark mode for Git GUI ? No, I am not asking for ways to edit those .tcl files. I tried that. Got myself comfortable with the whole page. But still, the menu bar and the window title bar remain white. And that frustates me a bit.

I have searched in Github Issues and Google Groups for the keyword dark but got no results I hoped so I'm posting this.

I'm a JS developer. But, I know a little bit of TCL and Tk and happily customised the About page like this. So, I think I can help. Just give me the Ok and I will go ahead.

[j6t]

I find it absolutely silly that each application must implement its own dark mode. It is the task of the desktop environment to offer a dark mode that is then propagated to all themed widgets of all applications. If your desktop environment can't do that, choose a different desktop environment. So, not interested.

What is desirable is that all UI elements for which Git GUI uses its own colors adapt to the darkness or lightness of theme in use.

[bronwen-org]

Would really appreciate this! to improve consistency and help save battery life.