Install syslinux-themes-ubuntu by entering the following commands in the terminal:
sudo apt update sudo apt install syslinux-themes-ubuntu
Description:
collection of boot loaders (theme metapackage)
SYSLINUX is a collection of boot loaders which operates off Linux ext2/3/4 or btrfs filesystems, MS-DOS FAT filesystems, network servers using PXE firmware, or from CD-ROMs. . This package depends on the package with the graphical bootloader theme for the matching Ubuntu release.
Version: 12
Section: universe/misc