Now there are many plugins you can use for transforming your WordPress admin section in your own colors. Now you know how to create your own color scheme, you know how to change frontend admin bar color as per admin color scheme selected in backend, you know how to randomly change color schemes as soon any new post is published or an old post updated and there are a lot more tips, tricks and plugin.
Now this tutorial is on new WordPress plugin called Default Admin Color Scheme, the plugin allows you to set a default admin color scheme for all users active on your site. Simply install and activate the Default Admin Color Scheme plugin. Upon activation visit your admin area Dashboard -> Settings -> General, scroll down to Admin Color Scheme section and select the default color scheme for all users. Also you can enable or disable users to select their own color schemes.