The link to Control Panel is what gives an instructor access to modify the course content and layout.  It is one of the few areas that is not visible to students

The look of the course can be modified here under the course options menu.  An instructor can change the buttons that are listed in the menu or the colors used. 

To change the buttons

From Control Panel                 

1. Under Course Options , select Course Design.

2. Select Course Menu Design.

3. In Select Menu Style, choose either to display course menu with buttons or in a text format.

4. If desired, in Style Properties, change the color scheme of course menu buttons.

5. To save changes and finish click Submit.