Should be an integer, it is compared with the result of
`display-color-cells'.
+`supports' (only match frames that support the specified face attributes)
+ Should be a list of face attributes. See the documentation for
+ the function `display-supports-face-attributes-p' for more
+ information on exactly how testing is done.
+
Read the section about customization in the Emacs Lisp manual for more
information."
;; It is better not to use backquote in this file,