How Change Submenu Colors, Etc., Universally?

I have many toolbars, each with many menus. Each menu has many submenus. I want to change the colors, etc., for all of the submenus only. How can I do that universally for all submenus in a toolbar, without going to each menu and changing the options for the submenus for that menu only?

---

Note: I do not want to change options (colors, etc.) for the menus. Just for the submenus.