Frenchtastic

This plugin allows you to give your WordPress dashboard a fresh new look. Your admin panel will look clean and will allow you to focus on what’s really important for you and your users. This colours scheme is set as default and the plugin also prevents users from changing it.

Coeur Admin Color Scheme

This plugin allows you to give your Wordpress dashboard a fresh new look.

Jick

<a href="http://www.jamesdimick.com/creations/olark-for-wordpress/" rel="nofollow ugc">Now Olark for WordPress!</a>

Coeur Admin Color Scheme vs Hab.la for WordPress