Note that In full-width mega menu items the background color is the same as the header's background color and cannot be set individually.
In order to achieve the effect where the edge of the menu item shows the background image as shown here:
...we have to set the last column of menu items as invisible. We can easily do that by adding the invisible class.
To do that, you have to reveal the classes property when you are editing the respective menu:
And in the column you want to hide add the invisible class:
