Remove purple from Ubuntu 16.04

gistfile1.txt

Remove grub background color:

16.04 and later:

sudo -H gedit /usr/share/plymouth/themes/ubuntu-logo/ubuntu-logo.grub

17.10 and later:

sudo -H gedit /usr/share/plymouth/themes/default.grub

And change the grub background color as you want, in my case I change grub background to black (0,0,0)

if background_color 0,0,0 ; then
   clear
fi

Then, update grub

sudo update-grub

https://askubuntu.com/questions/981614/how-can-i-change-the-purple-background-color-of-the-lock-screen-on-ubuntu-17-10

Change login screen background:

Simple way, you can change the login background using Nautilus:
open Nautilus (in root mode)
go to /usr/share/backgrounds.
cut/move/delete "warty-final-ubuntu.png"
then choose the picture you want ( .png format)
rename it to "warty-final-ubuntu.png"
then move it back to /usr/share/backgrounds.


Change Splash screen

sudo apt-get install 'plymouth-theme*'
 sudo update-alternatives --config default.plymouth
 
 Ubuntu studio is the best