--- a/tests/test-diff-color.t	Tue May 02 20:01:54 2017 +0200
+++ b/tests/test-diff-color.t	Tue May 02 20:19:09 2017 +0200
@@ -2,7 +2,7 @@
 
   $ cat <<EOF >> $HGRCPATH
   > [ui]
-  > color = always
+  > color = yes
   > formatted = always
   > [color]
   > mode = ansi
@@ -82,6 +82,22 @@
    a
    c
 
+(check that 'ui.color=always' force color)
+
+  $ hg diff --nodates --config ui.formatted=no --config ui.color=always
+  \x1b[0;1mdiff -r cf9f4ba66af2 a\x1b[0m (esc)
+  \x1b[0;31;1m--- a/a\x1b[0m (esc)
+  \x1b[0;32;1m+++ b/a\x1b[0m (esc)
+  \x1b[0;35m@@ -2,7 +2,7 @@\x1b[0m (esc)
+   c
+   a
+   a
+  \x1b[0;31m-b\x1b[0m (esc)
+  \x1b[0;32m+dd\x1b[0m (esc)
+   a
+   a
+   c
+
 --unified=2
 
   $ hg diff --nodates -U 2