Make whitespace-mode considerably more subtle; add palette mappings

The previous style involved the use of a dim grey background.  While
this is good to spot invisible characters quickly, it is bad for users
who want to run 'whitespace-mode' at all times (e.g. for Python which
is space-sensitive).

We thus remove the backgrounds by default but provide the option to
reinstate them via palette overrides (as documented at length in the
manual).  To this end, we have new semantic colour mappings for
ordinary negative space and its invisible characters:

- bg-space
- fg-space
- bg-space-err

1 files changed, 6 insertions, 0 deletions

diff --git a/ef-summer-theme.el b/ef-summer-theme.el
index 76e174e..2760ae2 100644
--- a/ef-summer-theme.el
+++ b/ef-summer-theme.el
@@ -231,6 +231,12 @@
       (mail-subject magenta-cooler)
       (mail-other magenta)
 
+;;;; Space mappings
+
+      (bg-space unspecified)
+      (fg-space border)
+      (bg-space-err bg-yellow-intense)
+
 ;;;; Tab mappings
 
       (bg-tab-bar      bg-alt)