The Nav Content Area has two settings:
Nav Content Width deals with the width of the main navigation area that holds the top-bar menu. The default setting is
75rem, which is equal to 1200px wide. You can change this to whatever you wish*.
Nav Content Background Color deals with the background color of the main navigation area. The default setting is
Once you have made your changes, click
Save & Publish
*I recommend that you always try to use rem values. There is a great tool that will help you with calculating rem values called Rem Calulator.