gtk-chtheme software package provides GTK+ 2.0 theme changer and previewer utility, 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 gtk-chtheme
gtk-chtheme is installed in your system.
Make ensure the gtk-chtheme package were installed using the commands given below,
$ sudo dpkg-query -l | grep gtk-chtheme *
You will get with gtk-chtheme package name, version, architecture and description in a table
| Distro | Ubuntu 14 04 lts trusty tahr |
| Section | X Window System software |
| Package | gtk-chtheme |
| Version | 0.3.1-5ubuntu1 |
| Description | GTK+ 2.0 theme changer and previewer utility |
| Sub Section | x11 |