Changing Login Color

The Situation

I didn’t really like the default shades of purple that Ubuntu uses for boot-up, so I wanted to change them to a pretty shade of green.

Stuff that didn't work

I tried changing the other instances of the aubergine purple by changing one of the instances of #2c001e, but to my knowledge, that did nothing.

The Solution

To change the color of the login screen:

  1. Type
    xhost +local: && sudo vim /etc/alternatives/gdm3.css
    You can change the editor to Emacs or whatever you like.
  2. Go to the block that begins with #lockdialogGroup, and change the hex color from #2c001e to whatever you want. I’m using #0a3621.
You know how there's a screen that appears before your lock screen? That screen was still purple, so I wanted to make that green as well.
  1. Type
    sudo vim /usr/share/plymouth/themes/ubuntu-logo/ubuntu-logo.script
  2. Go to the lines beginning with Window.SetBackground. There’ll be two of them.
  3. The default color on these lines is (0.16, 0.00, 0.12), which corresponds to #2c001e. Change this (on both lines) to whatever you want (these are ratios). I’m using (0.04, 0.21, 0.13) .
  4. Type
    sudo update-initramfs -u
  5. That should be it! Check out this link for more info.
When I boot up, there's a quick flash of purple that still appears, but I haven't yet figured out why that is.