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.

Kashiv

This plugin allows to have admin panel in different language (for example, admin’s native language) from blog’s home language. This is useful when you have blog in e.g. german but you want to have admin panel in english.
This plugin works simply. It adds a “Language” form element in user profile.
It works in Dashboard as well as on the blog’s homepage.

Admin Language

This plugin allows to have admin panel in different language (for example, admin's native language) from blog's home language.

Coeur Admin Color Scheme vs Admin Language