gdm-settings VS Sunflower

There is gdm settings https://github.com/gdm-settings/gdm-settings I have not used it a lot, so no idea if it can do what you are asking for.

AFAIK this allows you to mirror current user settings to the gdm session: https://github.com/gdm-settings/gdm-settings

You can use GDM Settings to modify the Login screen.

Use some utility like Login Manager (be aware that it may break things, specially on distros with custom GDM settings like Pop)

Or, going by this screenshot, you could apparently use the Login Manager Settings application as well.

You can use Login Manager Settings to both extract and modify the shell theme/css.

I currently have used / use https://github.com/realmazharhussain/gdm-settings . works like a dream

To theme the display manager i don’t know of manual way but there is this app

Ideally I'd love my own file manager Sunflower to get picked up but last time I spoke to someone from Debian project they decided to not to do so because I have my own coding style for it instead of being religious about PEP8. Things are already in place for the most part since I have make script for generating .deb files and packages work fine across many distributions. I try to keep number of dependencies as low as possible. Been slacking with updates lately due to my work eating at my life, but I can get more time for it should changes be needed for its acceptance.

There's also Sunflower.

In response to AutoModerator post, I actually thought GitHub was preferred, so I posted that repository. In fact, my main repository is on GitLab, even though they don't have concept "releases" like GitHub does.