Tried to find other similar questions, but didn't find any.

Ubuntu (18.04.2)

When booting Ubuntu, at the login panel, i have applied an theme, and everything is working fine. The problem is that, when i wake up Ubuntu from suspend mode, the login panel is still the default one that Ubuntu use.

tried to change the LogDialogGroup with:

#lockDialogGroup {
background: #2c001e url(file:///home/wsu/Pictures/Wallpapers/astronomy.jpg);
background-repeat: no-repeat;
background-size: cover;
background-position: center;

Important: That changed the the login screen background image, but takes effect after the second time that i have to login, when the computer comes out of suspend mode. When loging in for first time (bootup login) the login screen is: login

enter image description here

After the first time, when i have to login again, that's the screen: next login

Simply explained, i want to see the first screen every time that i login.

Result from env | grep DESKTOP_SESSION: enter image description here

i followed the instructions from there to apply the login theme: https://github.com/daniruiz/flat-remix-gnome/blob/master/README.md

  • Which theme did you apply? The first login screen is GDM3, while the lock screen is GNOME. You only applied a GDM3 theme. – danzel May 24 at 8:16
  • i have applied the flat-remix login theme. Tried to search "Gnome login theme" on google, but the results is for GDM themes only. What i can do ? – Alex Kalaidjiev May 24 at 9:29
  • @Alex search for "gnome shell themes". – danzel May 24 at 14:02
  • There seems to be a flat-remix gnome shell theme as well. – danzel May 24 at 14:05
  • @AlexKalaidjiev this bug is fixed in 19.04 – tatsu May 24 at 14:25

Please note that this answer is for this particular case/ Question only after having the comments and outputs..

Login-Screen theming

Login Screen is themed by the file /etc/alternatives/gdm3.css this is a linked file and not the actual file..

to know which file is used you can use two ways..

  1. ls -l /etc/alternatives/gdm3.css


parrot@i7-4770U:~$ ls -l /etc/alternatives/gdm3.css
lrwxrwxrwx 1 root root 56 May 25 08:06 /etc/alternatives/gdm3.css -> /usr/share/themes/Flat-Remix/gnome-shell/gnome-shell.css

from the above output it is observed that .../Flat-Remix/gnome-shell/gnome-shell.css is the one used at login screen..

  1. run sudo update-alternatives --config gdm3.css and look for the * mark


parrot@i7-4770U:~$ sudo update-alternatives --config gdm3.css
[sudo] password for parrot: 
There are 12 choices for the alternative gdm3.css (providing /usr/share/gnome-shell/theme/gdm3.css).

  Selection    Path                                                                           Priority   Status
* 0            /usr/share/themes/Flat-Remix/gnome-shell/gnome-shell.css                        20        auto mode
  1            /usr/share/gnome-shell/theme/P1.css                                             15        manual mode
  2            /usr/share/gnome-shell/theme/ubuntu.css                                         10        manual mode
  3            /usr/share/themes/Flat-Remix-Dark-fullPanel/gnome-shell/gnome-shell.css         17        manual mode
  4            /usr/share/themes/Flat-Remix-Dark/gnome-shell/gnome-shell.css                   17        manual mode
  5            /usr/share/themes/Flat-Remix-Darkest-fullPanel/gnome-shell/gnome-shell.css      17        manual mode
  6            /usr/share/themes/Flat-Remix-Darkest/gnome-shell/gnome-shell.css                17        manual mode
  7            /usr/share/themes/Flat-Remix-Miami-Dark-fullPanel/gnome-shell/gnome-shell.css   17        manual mode
  8            /usr/share/themes/Flat-Remix-Miami-Dark/gnome-shell/gnome-shell.css             17        manual mode
  9            /usr/share/themes/Flat-Remix-Miami-fullPanel/gnome-shell/gnome-shell.css        17        manual mode
  10           /usr/share/themes/Flat-Remix-Miami/gnome-shell/gnome-shell.css                  17        manual mode
  11           /usr/share/themes/Flat-Remix-fullPanel/gnome-shell/gnome-shell.css              17        manual mode
  12           /usr/share/themes/Flat-Remix/gnome-shell/gnome-shell.css                        20        manual mode

Press <enter> to keep the current choice[*], or type selection number: 

So it is clear that login screen .css file can be found in these above two ways and thus editing it will make required changes for login screen only..

Unlock-Screen theming

this depends upon the Desktop Session you are using..

to know which desktop session you are using, you can run the below command



parrot@i7-4770U:~$ env | grep DESKTOP_SESSION

from the above output it is observed that the DESKTOP_SESSION is ubuntu which is the default one..

for the default desktop session in Ubuntu 18.04 the style sheet is defined in the file /usr/share/gnome-shell/modes/ubuntu.json

So open the file in a terminal with the below command

nano /usr/share/gnome-shell/modes/ubuntu.json


    "parentMode": "user",
    "stylesheetName": "ubuntu.css",
    "enabledExtensions": ["ubuntu-dock@ubuntu.com", "ubuntu-appindicators@ubuntu.com"]

in the above ubuntu.css means /usr/share/gnome-shell/themes/ubuntu.css is the file for both default Shell Theme and for Unlock-Screen..

so, to have the same effect of login screen theming on Unlock-screen.. we have two options..

either changing the file name/path ubuntu.css or replacing the contents in ubuntu.css with the flat-remix-gnome which is used at login screen..

in this particular case the best option is to change the file name/path like this by editing /usr/share/gnome-shell/modes/ubuntu.json

    "parentMode": "user",
    "stylesheetName": "Flat-Remix/gnome-shell.css",
    "enabledExtensions": ["ubuntu-dock@ubuntu.com", "ubuntu-appindicators@ubunt$

this means default shell theme and unlock-screen both uses this Flat-Remix/gnome-shell.css file..

So for login screen theming you have to open the file with below command

sudo -H gedit /etc/alternatives/gdm3.css

and for unlock-screen/ default shell theme

sudo -H gedit /usr/share/gnome-shell/theme/Flat-Remix/gnome-shell.css

enter image description here

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