gnome-shell-theme-elegance-colors, не устанавливающий

Я запускаю Ubuntu GNOME 16.04.1. Я пытаюсь установить тему Цветов Элегантности с помощью инструкций здесь: https://github.com/numixproject/elegance-colors

Однако я не могу установить его, поскольку "пакет не может быть расположен". Я записал те же точные операторы в терминал как показано в ссылке, но это все еще не работает. Вот вывод, я вхожу в терминал:

anurag@Anurag-Lenovo-G50-80:~$ sudo add-apt-repository ppa:satyajit-happy/themes
[sudo] password for anurag: 
This PPA contains various themes for Gnome and Xfce.
More info: https://launchpad.net/~satyajit-happy/+archive/ubuntu/themes
Press [ENTER] to continue or ctrl-c to cancel adding it

gpg: keyring `/tmp/tmpbb1ar3tg/secring.gpg' created
gpg: keyring `/tmp/tmpbb1ar3tg/pubring.gpg' created
gpg: requesting key 5F0D930C from hkp server keyserver.ubuntu.com
gpg: /tmp/tmpbb1ar3tg/trustdb.gpg: trustdb created
gpg: key 5F0D930C: public key "Launchpad PPA for Satyajit Sahoo" imported
gpg: Total number processed: 1
gpg:               imported: 1  (RSA: 1)
OK
anurag@Anurag-Lenovo-G50-80:~$ sudo apt-get update
Hit:1 http://us.archive.ubuntu.com/ubuntu xenial InRelease
Get:2 http://security.ubuntu.com/ubuntu xenial-security InRelease [94.5 kB]                                                             
Get:3 http://us.archive.ubuntu.com/ubuntu xenial-updates InRelease [95.7 kB]                                                                         
Hit:4 http://archive.canonical.com/ubuntu xenial InRelease                                                                                           
Ign:5 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial InRelease                               
Hit:6 http://us.archive.ubuntu.com/ubuntu xenial-backports InRelease                 
Ign:7 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial Release
Get:8 http://us.archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages [328 kB]
Ign:9 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main amd64 Packages
Ign:10 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main i386 Packages
Get:11 http://us.archive.ubuntu.com/ubuntu xenial-updates/main i386 Packages [323 kB]
Get:12 http://us.archive.ubuntu.com/ubuntu xenial-updates/universe amd64 Packages [300 kB]
Ign:13 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main all Packages
Get:14 http://us.archive.ubuntu.com/ubuntu xenial-updates/universe i386 Packages [297 kB]
Ign:15 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main Translation-en_US
Ign:16 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main Translation-en
Ign:17 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:18 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main DEP-11 64x64 Icons
Ign:9 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main amd64 Packages
Ign:10 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main i386 Packages
Ign:13 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main all Packages
Ign:15 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main Translation-en_US
Ign:16 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main Translation-en
Ign:17 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:18 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main DEP-11 64x64 Icons
Ign:9 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main amd64 Packages
Ign:10 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main i386 Packages
Ign:13 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main all Packages
Ign:15 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main Translation-en_US
Ign:16 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main Translation-en
Ign:17 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:18 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main DEP-11 64x64 Icons
Ign:9 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main amd64 Packages
Ign:10 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main i386 Packages
Ign:13 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main all Packages
Ign:15 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main Translation-en_US
Ign:16 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main Translation-en
Ign:17 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:18 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main DEP-11 64x64 Icons
Ign:9 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main amd64 Packages
Ign:10 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main i386 Packages
Ign:13 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main all Packages
Ign:15 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main Translation-en_US
Ign:16 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main Translation-en
Ign:17 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:18 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main DEP-11 64x64 Icons
Err:9 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main amd64 Packages
  404  Not Found
Ign:10 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main i386 Packages
Ign:13 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main all Packages
Ign:15 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main Translation-en_US
Ign:16 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main Translation-en
Ign:17 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:18 http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial/main DEP-11 64x64 Icons
Fetched 1,439 kB in 5s (287 kB/s)
Reading package lists... Done
W: The repository 'http://ppa.launchpad.net/satyajit-happy/themes/ubuntu xenial Release' does not have a Release file.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: Failed to fetch http://ppa.launchpad.net/satyajit-happy/themes/ubuntu/dists/xenial/main/binary-amd64/Packages  404  Not Found
E: Some index files failed to download. They have been ignored, or old ones used instead.
anurag@Anurag-Lenovo-G50-80:~$ sudo apt-get install gnome-shell-theme-elegance-colors
Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Unable to locate package gnome-shell-theme-elegance-colors

Я не могу выяснить то, чем могла быть причина и как зафиксировать ее. Я действительно люблю эту тему и хочу ее. Помогите.

Спасибо.