@author: dhduc
Install Grub Customizer:
sudo add-apt-repository ppa:danielrichter2007/grub-customizer -y
sudo apt-get update
sudo apt-get install grub-customizer -y
Copy UbuntuGrub to boot grub theme folder:
sudo cp -r UbuntuGrub /boot/grub/themes
Make sure that /boot/grub/themes folder exist, if not please create it.
Open Grub Customizer with Admintrator privileges
In Appearance Setting tab, chose UbuntuGrub for Theme field, click Save button.
That's all!
Note: If not see the UbuntuGrub, please restart the Grub Customizer.