sudo cp /usr/share/themes/ZorinBlue-Dark/gnome-shell/gnome-shell-theme.gresource{,.bak}
cd /usr/share/themes/ZorinBlue-Dark/gnome-shell
sudo glib-compile-resources /usr/share/themes/ZorinBlue-Dark/gnome-shell/gnome-shell-theme.gresource.xml
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Note: I don't know where 'Login Manager Settings' stores its settings, but I have noticed that my method is no longer working consistently after it has been used.
Even after setting the background type back to “None”, the operation becomes erratic:
So, to sum up, my one piece of advice is to forget my code and only use Login Manager Settings v.2 to change the background of Zorin 17 Core login screen in GDM mode.
It's safer... and, I aggree with you @Forpli, simpler.
In fact, as I've learned since my main distribution switched to Ubuntu 24.04, AppImages don't even launch, probably due to sandboxing issues.
I've learned how to fix them, but I don't enjoy being caught up in this kind of problem. So I didn't go any further. You can't really say I tried.
If you want to try it, you have to add “--no-sandbox” to the command line to launch AppImages.
Extract the archive, right-click on the unzipped directory, choose “Open in terminal” and enter this line, while adjusting the path to the image you want:
just wanna say, i did this as described, but it did not pair or change my background fully as intended. it simply bugged out on the first reboot, and then defaulted to the light theme background on the second.
HOWEVER. it did make a handy new gdm folder in /usr/share/backgrounds. makeing the picture file in there the default login background. And if i just changed the name of the default background picture in there and replaced it with my own, giving my new picture the same name as the default (gdm-wallpaper). it worked. you do have to do all the moveing and name changeing through Nautilus admin:/ but it was easy with one normal filemanager open along the admin one. thanks for this article. I have been scratching my head since I installed Zorin a month ago. first to figure out how the hell to get the admin manager to work (even tho the terminal told me when I tried to run just nautilus. I'm slow okay XD) and then getting to this step.
Just wanted to add this here for anyone like me trying this in 2026. and wondering why their background didn't change useing the script. I opened the "read me" and ran the
sudo ./sync_desktop_wallpaper_to_login.sh
command after the one mentioned as well. that could be what made the gmd folder? Someone techier than me will have to test what specifically though. worth a try at least, and does work, just not FULLY as intended, at least for me. As in, I still had to go change the picture myself, but it did make a handy, simple path for me to do so without potentially breaking my system. This is the least complicated method I have seen to change that pesky startup background. It's a small detail, but it matters to a lot of us.
ah yeah, i figured it out on my laptop after. I have Zorin 18 installed on my laptop and my desktop. i am a little more confident with playing around on mylaptop, cause i can easily just reinstall Zorin there if I mess up, as all my valuable files are on the cloud. it's just for volunteer work and on-the-go stuff, so all my files are just shared and stored on the clouds there. It does work, you're right. I tried to say in my original comment that it DID work for me, even with the roundabout way I found. I just had some problems figuring it out at first.
didn't realize that the picture I wanted to change it to HAD to be in the "/pictures" directory. thought it might be cleaner to have it from my backgrounds folder, either in "/.local/share/..." or straight from "/usr/..." It easily mirrored my background for the login screen. but took me a minute to realise changing it to a different kind had to be from my "/pictures directory", and thus just placing a picture in the gdm folder it created, deleting the original picture there, and renaming the picture I placed there and wanted as my background to "gdm-wallpaper" was easier for me at that moment. And that also did work.
That said, I just got done getting GDM back up and running. ran into an error where it wouldn't load after a restart, and had clogged up 600gb of the error.log file. (I thought a restart would fix it. I should have deleted or cleaned it before restarting, lesson learned.) thank god for the linux comunity haveing helpful guides. So I could clean out the space I needed and reinstall it. had to do it all from the scary terminal with no visual as a linux noob
No idea if that was because I went about it that way round about way, or if it was just that I waited too long after downloading some system updates before rebooting. might just be that it broke and needed a reinstall after that update anyway. but thought I'd mention it while I was at it. At least I learned something new and how to fix it.
if you have a backup drive (i have 2x 1TB external)
then please have a look in the software store for
'back in time' it will take a snap shot of your entire system
that way you can play reinstall and then bring back the last good copy of your system.
and only use Login Manager Settings v.2 to change the background of Zorin 17 Core login screen in GDM mode.
