$ sudo apt-get update
$ sudo apt-get install plymouth-theme-ubuntustudio 

plymouth-theme-ubuntustudio is installed in your system.

Make ensure the plymouth-theme-ubuntustudio package were installed using the commands given below,

$ sudo dpkg-query -l | grep plymouth-theme-ubuntustudio *

You will get with plymouth-theme-ubuntustudio package name, version, architecture and description in a table

plymouth-theme-ubuntustudio package basic information: