The theme includes 3 labels that you can add via class to your menu sub-items.
The class are:
Please go in your dashboard > appearance > customize > headers > labels and customize the color as you like.
You can add the css classes that you want to add in the “CSS classes” of the sub menu items you need to add
If the “Css classes” of your menu item are not enable by default please:
Go to admin > appearance > menu.
Click on “Screen Options” (top right of the screen)
Check the “CSS classes” options in the “Show advanced menu properties” panel.
now you can add your css classes to the element.