There are a couple of things I like to do when I install WordPress for the first time: I like to change up the admin theme and customize it with branding appropriate to the context; customize the dashboard by removing unnecessary widgets and perhaps adding a few of my own; and finally, I also like to brand the login screen.

These are just a few of the things that help me get acclimated to my environment, and also to customize the experience for myself and whatever client I’m installing this for.

This plugin takes care of a lot of that, and will allow you to customize the css where appropriate for the WordPress admin and login screens. I didn't add this to the official WordPress repository because this is isn't really designed for the average user, but more for the developer, and so I suggest after downloading the plugin you use this as a base for your installation rather than as is.

Happy customizing!

1. Once you've got the files unarchived, please consider editing the plugin to work best with your situation. There are multiple options available for what you can do to modify the admin screen.
2. After you're done modifying the plugin, upload it to your plugins directory and activate it.

This plugin is no longer supported. Might or might not work.