gistfile1.txt

(global-set-key (kbd "M-?") 'flash-active-buffer)

(make-face 'flash-active-buffer-face)
(set-face-attribute 'flash-active-buffer-face nil
                    :background "red"
                    :foreground "black")
(defun flash-active-buffer ()
  (interactive)
  (run-at-time "100 millisec" nil
               (lambda (remap-cookie)
                 (face-remap-remove-relative remap-cookie))
               (face-remap-add-relative 'default 'flash-active-buffer-face)))