Green Boxes on Instrument Panel

Click zone visualization allows users to see which controls within the cockpit are interactive. These green boxes can be turned on or off in the Main Menu under the General settings tab. 

To turn green boxes on, go to the General tab, and under Flight Model, select "Show clickable regions in the cockpit."

In addition, toggling “Show Instrument Descriptions” will display the name of the instrument when you hover the mouse pointer over it.