If you are interested in disabling this because it just gets in the way, here's one way.
For Chrome - install Stylish add-on.
Open your browser and navigate to your Controller URL. Click on the "S" icon at the upper right to launch the Stylish ...
There are other things that this affects (some icons on the App Dashboard), so you can turn the Styles ON/OFF very quickly and easily by clicking the "S" icon hit the "slider" to off.