You probably want to use the face-remap package included in Emacs
instead of manipulating face-remapping-alist directly. Note that many
-of the functions inthat package modify the list destructively, so make
-sure to set it to a fresh value (for instance, use `copy-tree' as in
-the example above).
+of the functions in that package modify the list destructively, so make
+sure you set it to a fresh value (for instance, use `copy-tree' as in
+the example above) before modifying.
Because Emacs normally only redraws screen areas when the underlying
buffer contents change, you may need to call `redraw-display' after