legacyhuman-theme software package provides Legacy Human GTK theme, you can install in your Ubuntu 17.04 (Zesty Zapus) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install legacyhuman-theme
legacyhuman-theme is installed in your system.
Make ensure the legacyhuman-theme package were installed using the commands given below,
$ sudo dpkg-query -l | grep legacyhuman-theme *
You will get with legacyhuman-theme package name, version, architecture and description in a table
| Distro | Ubuntu 17 04 zesty zapus |
| Section | X Window System software |
| Package | legacyhuman-theme |
| Version | 0.1-0ubuntu2 |
| Description | Legacy Human GTK theme |
| Sub Section | x11 |