gnome-themes-ubuntu software package provides Ubuntu community themes, you can install in your Ubuntu 14.04 LTS (Trusty Tahr) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install gnome-themes-ubuntu
gnome-themes-ubuntu is installed in your system.
Make ensure the gnome-themes-ubuntu package were installed using the commands given below,
$ sudo dpkg-query -l | grep gnome-themes-ubuntu *
You will get with gnome-themes-ubuntu package name, version, architecture and description in a table
| Distro | Ubuntu 14 04 lts trusty tahr |
| Section | GNOME |
| Package | gnome-themes-ubuntu |
| Version | 0.6.1 |
| Description | Ubuntu community themes |
| Sub Section | GNOME |