With the introduction of WordPress 3.8 your WordPress powered site now has an all new look in its admin area. You are able to choose from several colors to style the look and feel of your back end.
When you first install 3.8 your theme color will automatically be changed to the new default settings which is a dark/light contrast theme. If you want to change this, go to “Users” then click “Your Profile” and you will see a section called “admin panel color scheme” where you can change the look.