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?

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

I'm sorry, there are no any other ways (may be just direct editing of tlbdata.xml files)

This would be a very useful improvement.