* themes/tango-dark-theme.el: Tweak background on low-color terminals.

etc/ChangeLog

+2011-02-21  Chong Yidong  <cyd@stupidchicken.com>
+
+	* themes/tango-dark-theme.el: Tweak background on low-color
+	terminals.
+
 2011-02-17  Ken Manheimer  <ken.manheimer@gmail.com>
 
 	* etc/images/icons/allout-widgets/dark-bg,

etc/themes/tango-dark-theme.el

@@ -49,7 +49,13 @@ Semantic, and Ansi-Color faces are included.")
 
   (custom-theme-set-faces
    'tango-dark
-   `(default ((,class (:foreground ,alum-1 :background ,alum-6))))
+   ;; Ensure sufficient contrast on low-color terminals.
+   `(default ((((class color) (min-colors 4096))
+	       (:foreground ,alum-1 :background ,alum-6))
+	      (((class color) (min-colors 256))
+	       (:foreground ,alum-1 :background "#222"))
+	      (,class
+	       (:foreground ,alum-1 :background "black"))))
    `(cursor ((,class (:foreground ,alum-6 :background ,butter-1))))
    ;; Highlighting faces
    `(fringe ((,class (:background ,alum-7))))