Adjust colors of help-key-binding face for readability

* lisp/faces.el (help-key-binding): Adjust colors for improved
readability, and use a flat :box for highlighting (with negative
:line-width height to avoid any vertical resizing of the minibuffer).

This was discussed in:
https://lists.gnu.org/r/emacs-devel/2021-03/msg00535.html

diff --git a/lisp/faces.el b/lisp/faces.el
index 1e668a43f43621880c2f3a9b2035c97bdfe863f1..ec650e30cab56d2575af192f9121a1e1e67da974 100644 (file)
--- a/lisp/faces.el
+++ b/lisp/faces.el
@@ -2816,8 +2816,12 @@ Note: Other faces cannot inherit from the cursor face."
   :group 'help)
 
 (defface help-key-binding
-  '((((class color) (min-colors 88) (background light)) :background "grey90")
-    (((class color) (min-colors 88) (background dark)) :background "grey25")
+  '((((class color) (min-colors 88) (background light))
+     :background "grey92" :foreground "DarkBlue"
+     :box (:line-width (1 . -1) :color "grey80"))
+    (((class color) (min-colors 88) (background dark))
+     :background "grey23" :foreground "LightBlue"
+     :box (:line-width (1 . -1) :color "grey35"))
     (((class color grayscale) (background light)) :background "grey90")
     (((class color grayscale) (background dark)) :background "grey25")
     (t :background "grey90"))