Change login screen purple background 18.10

Question

This is almost a dup of this question, but with a slight variation.

Instead of using a picture file for the login screen background, I'd like to use the same solid color background that I've set for the lock screen in the Background settings panel.

Where are the lock screen solid color panels located? What mod to the referenced question would I need to make? Could I just place a renamed copy of the solid color panel where the current background file is, so that I don't have to modify the gdm3.css file?

I'm looking for the easiest way.

Answer 1

to change the login screen color equivalent to those 15 colors which are available when we open Settings>Background>LockScreen>color

first set the required color as lockscreen from the settings>background>lockscreen>color

to know the value of this color run the below command.

gsettings get org.gnome.desktop.screensaver primary-color

Example:

pratap@i7-6550U:~$ gsettings get org.gnome.desktop.screensaver primary-color
'#7a8aa2'
pratap@i7-6550U:~$ 

Copy the color, in above case it is #7a8aa2

now we need to edit the gdm3.css file.

open the file with your favorite editor, mine is gedit. so
sudo -H gedit /etc/alternatives/gdm3.css

go to line number around 1985 & 1986 and find the below content.

#lockDialogGroup {
  background: none;
  background-color: none;
  background-gradient-direction: vertical;
  background-gradient-start: #6D2169;
  background-gradient-end: #370026; }

change the content with

#lockDialogGroup {
  background: none;
  background-color: none;
  background-gradient-direction: vertical;
  background-gradient-start: #7a8aa2;
  background-gradient-end: #7a8aa2; }

here in the line number 1985 & 1986 put the color you want in place of #7a8aa2

save the file, close & reboot to see the change.

these are the 15 colors + default one.

#7a634b
#425265
#475b52
#888888
#7a8aa2
#ff89a9
#ed9116
#d272c4
#437740
#fad166
#ab2876
#5d479d
#008094
#db5d33
#000000
#023c88

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