Next: How do I execute (“evaluate”) a piece of Emacs Lisp code?, Previous: How do I repeat a command as many times as possible?, Up: Common requests [Contents][Index]
See X Resources in The GNU Emacs Manual.
You can also use a resource editor, such as editres (for X11R5 and onwards), to look at the resource names for the menu bar, assuming Emacs was compiled with the X toolkit.