Grub on start up changed color from purple to black? A while ago, i reinstalled 12.04 on my computer and a few day later when My system restarts after updating itself, the grub is no longer purple. It is  just black and I didn't change anything that could do that. my system works fine and there is no problems with anything. I just don't like looking at a black grub while waiting in the booting process. Can you change the grub back to being purple or choose a different color?

In terminal type
sudo gedit /lib/plymouth/themes/default.grub



*

*for Saucy:
sudo gedit /lib/plymouth/themes/ubuntu-logo/ubuntu-logo.grub


*for Bionic (18.04)
sudo gedit /usr/share/plymouth/themes/ubuntu-gnome-logo/ubuntu-gnome-logo.grub

And you can change the grub background colour by changing the values of the 3 in numbers in the text document.    
Black is this   
if background_color 0,0,0 ; then
   clear
fi

and purple is this
if background_color 44,0,30 ; then
    clear
fi

Once you have finished editing that file save it and run
sudo update-grub

Refrences here and here.

Spent an hour trying to figure this out on Ubuntu 16...no posted solutions worked but good news I figured out how to do this, it easy!
in terminal;
sudo gedit /boot/grub/grub.cfg

search for "background" and change

### BEGIN /etc/grub.d/05_debian_theme ###
      set menu_color_normal=white/black
      set menu_color_highlight=black/light-gray
      if background_color 45,51,53; then
clear
      fi
      ### END /etc/grub.d/05_debian_theme ###

to

### BEGIN /etc/grub.d/05_debian_theme ###
      set menu_color_normal=white/black
      set menu_color_highlight=black/light-gray
      #if background_color 45,51,53; then
      #  clear
      fi
      ### END /etc/grub.d/05_debian_theme ###

*you need to comment out if background... and clear.
save. reboot!
This makes grub look far nicer when used to dual boot a Windows 10.