Use custom-set-faces! instead and update the cons message

modules/ui/window-select/README.org

@@ -48,14 +48,15 @@ The first character of the buffers changes to a highlighted, user-selectable
 character.
 
  + Pros: the content of the buffers are always visible.
- + Cons: Requires custom configuration to show large letters.
+ + Cons: The display characters are small and difficult to see (see below for a way to enlarge them).
  
 **** Custom font-face example
 This changes the ace-window display to show a white letter with a red background. The box attribute adds some padding.
 #+BEGIN_SRC elisp
-  (custom-set-faces
+(custom-set-faces!
   '(aw-leading-char-face
-     ((t (:foreground "white" :background "red" :weight bold :height 2.5 :box (:line-width 10 :color "red"))))))
+    :foreground "white" :background "red"
+    :weight bold :height 2.5 :box (:line-width 10 :color "red")))
 #+END_SRC 
 
 ** switch-window