want changes to submenu applied to all submenus

I have toolbars with many menus; some as many as 100. Some of those menus have submenus. I want each menu to have the same color scheme. No problem. I want each submenu to have the same color scheme (different from the menu color scheme). How do I get the same color scheme for each submenu without manually having to change the submenu options in every menu--that is, manually editing 100 menus.