diff --git a/app/assets/stylesheets/dark.css b/app/assets/stylesheets/dark.css
index 4ba768b9b..e9fff8a86 100644
--- a/app/assets/stylesheets/dark.css
+++ b/app/assets/stylesheets/dark.css
@@ -354,6 +354,12 @@ div.wiki table, div.wiki td, div.wiki th { border-color: var(--oc-gray-4); }
   border-color: #adb5bd;
 }
 
+/* Pages without #wrapper, such as the wiki syntax help pages */
+body { background-color: var(--color-background); }
+
+/* Wiki toolbar icons on the wiki syntax help pages */
+th > img[src*="/jstoolbar/"] { filter: invert(1) hue-rotate(180deg); }
+
 /* Distinguish buttons from text fields */
 input[type="submit"], button[type="submit"], input[type="button"] { background-color: var(--oc-gray-1); }
 
diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index ca428e464..8024fba54 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -946,6 +946,11 @@ module ApplicationHelper
     end
   end
 
+  # Returns the head tags for the wiki syntax help pages
+  def heads_for_wiki_syntax(stylesheet)
+    safe_join([stylesheet_link_tag(stylesheet), color_scheme_tags])
+  end
+
   # Returns the theme, controller name, and action as css classes for the
   # HTML body.
   def body_css_classes
diff --git a/app/views/help/wiki_syntax/code_highlighting_languages.html.erb b/app/views/help/wiki_syntax/code_highlighting_languages.html.erb
index befa388a4..e34c61643 100644
--- a/app/views/help/wiki_syntax/code_highlighting_languages.html.erb
+++ b/app/views/help/wiki_syntax/code_highlighting_languages.html.erb
@@ -3,7 +3,7 @@
 <head>
   <title>List of languages supported by Redmine code highlighter</title>
   <meta charset="UTF-8">
-  <%= stylesheet_link_tag "wiki_syntax_detailed.css" %>
+  <%= heads_for_wiki_syntax "wiki_syntax_detailed" %>
 </head>
 
 <body>
diff --git a/app/views/help/wiki_syntax/common_mark/de/wiki_syntax_common_mark.html.erb b/app/views/help/wiki_syntax/common_mark/de/wiki_syntax_common_mark.html.erb
index 407c8b41e..b4f934a98 100644
--- a/app/views/help/wiki_syntax/common_mark/de/wiki_syntax_common_mark.html.erb
+++ b/app/views/help/wiki_syntax/common_mark/de/wiki_syntax_common_mark.html.erb
@@ -3,7 +3,7 @@
 <head>
 <meta charset="UTF-8">
 <title>Wikiformatierung</title>
-<%= stylesheet_link_tag "wiki_syntax.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax" %>
 </head>
 <body>
 
diff --git a/app/views/help/wiki_syntax/common_mark/de/wiki_syntax_detailed_common_mark.html.erb b/app/views/help/wiki_syntax/common_mark/de/wiki_syntax_detailed_common_mark.html.erb
index b9e7a7e24..93e377a77 100644
--- a/app/views/help/wiki_syntax/common_mark/de/wiki_syntax_detailed_common_mark.html.erb
+++ b/app/views/help/wiki_syntax/common_mark/de/wiki_syntax_detailed_common_mark.html.erb
@@ -3,7 +3,7 @@
 <head>
 <title>Redmine Wiki-Formatierung (CommonMark Markdown (GitHub Flavored))detailliert</title>
 <meta charset="UTF-8">
-<%= stylesheet_link_tag "wiki_syntax_detailed.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax_detailed" %>
 </head>
 
 <body>
diff --git a/app/views/help/wiki_syntax/common_mark/en/wiki_syntax_common_mark.html.erb b/app/views/help/wiki_syntax/common_mark/en/wiki_syntax_common_mark.html.erb
index a0e7f005d..f2d8df9d8 100644
--- a/app/views/help/wiki_syntax/common_mark/en/wiki_syntax_common_mark.html.erb
+++ b/app/views/help/wiki_syntax/common_mark/en/wiki_syntax_common_mark.html.erb
@@ -3,7 +3,7 @@
 <head>
 <meta charset="UTF-8">
 <title>Wiki formatting</title>
-<%= stylesheet_link_tag "wiki_syntax.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax" %>
 </head>
 <body>
 
diff --git a/app/views/help/wiki_syntax/common_mark/en/wiki_syntax_detailed_common_mark.html.erb b/app/views/help/wiki_syntax/common_mark/en/wiki_syntax_detailed_common_mark.html.erb
index 3f9793eba..909cec982 100644
--- a/app/views/help/wiki_syntax/common_mark/en/wiki_syntax_detailed_common_mark.html.erb
+++ b/app/views/help/wiki_syntax/common_mark/en/wiki_syntax_detailed_common_mark.html.erb
@@ -3,7 +3,7 @@
 <head>
 <title>RedmineWikiFormatting (CommonMark Markdown (GitHub Flavored))</title>
 <meta charset="UTF-8">
-<%= stylesheet_link_tag "wiki_syntax_detailed.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax_detailed" %>
 </head>
 
 <body>
diff --git a/app/views/help/wiki_syntax/common_mark/ja/wiki_syntax_common_mark.html.erb b/app/views/help/wiki_syntax/common_mark/ja/wiki_syntax_common_mark.html.erb
index 2e6c1314e..a6ffaa932 100644
--- a/app/views/help/wiki_syntax/common_mark/ja/wiki_syntax_common_mark.html.erb
+++ b/app/views/help/wiki_syntax/common_mark/ja/wiki_syntax_common_mark.html.erb
@@ -3,7 +3,7 @@
 <head>
 <meta charset="UTF-8">
 <title>Wiki formatting</title>
-<%= stylesheet_link_tag "wiki_syntax.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax" %>
 </head>
 <body>
 
diff --git a/app/views/help/wiki_syntax/common_mark/ja/wiki_syntax_detailed_common_mark.html.erb b/app/views/help/wiki_syntax/common_mark/ja/wiki_syntax_detailed_common_mark.html.erb
index 83ce78646..62547b370 100644
--- a/app/views/help/wiki_syntax/common_mark/ja/wiki_syntax_detailed_common_mark.html.erb
+++ b/app/views/help/wiki_syntax/common_mark/ja/wiki_syntax_detailed_common_mark.html.erb
@@ -3,7 +3,7 @@
 <head>
 <title>RedmineWikiFormatting (CommonMark Markdown (GitHub Flavored))</title>
 <meta charset="UTF-8">
-<%= stylesheet_link_tag "wiki_syntax_detailed.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax_detailed" %>
 </head>
 
 <body>
diff --git a/app/views/help/wiki_syntax/common_mark/ta-in/wiki_syntax_common_mark.html.erb b/app/views/help/wiki_syntax/common_mark/ta-in/wiki_syntax_common_mark.html.erb
index 165251faa..421239785 100644
--- a/app/views/help/wiki_syntax/common_mark/ta-in/wiki_syntax_common_mark.html.erb
+++ b/app/views/help/wiki_syntax/common_mark/ta-in/wiki_syntax_common_mark.html.erb
@@ -2,7 +2,7 @@
 <html>
   <meta charset="UTF-8">
   <title>விக்கி வடிவமைப்பு</title>
-  <%= stylesheet_link_tag "wiki_syntax.css" %>
+  <%= heads_for_wiki_syntax "wiki_syntax" %>
 </head>
 <body>
 
diff --git a/app/views/help/wiki_syntax/common_mark/ta-in/wiki_syntax_detailed_common_mark.html.erb b/app/views/help/wiki_syntax/common_mark/ta-in/wiki_syntax_detailed_common_mark.html.erb
index 14b90d610..67cffaaf3 100644
--- a/app/views/help/wiki_syntax/common_mark/ta-in/wiki_syntax_detailed_common_mark.html.erb
+++ b/app/views/help/wiki_syntax/common_mark/ta-in/wiki_syntax_detailed_common_mark.html.erb
@@ -3,7 +3,7 @@
 <head>
   <title>RedmineWikiFormatting (CommonMark Markdown (GitHub Flavored))</title>
   <meta charset="UTF-8">
-  <%= stylesheet_link_tag "wiki_syntax_detailed.css" %>
+  <%= heads_for_wiki_syntax "wiki_syntax_detailed" %>
 </head>
 
 <body>
diff --git a/app/views/help/wiki_syntax/textile/bg/wiki_syntax_detailed_textile.html.erb b/app/views/help/wiki_syntax/textile/bg/wiki_syntax_detailed_textile.html.erb
index ff262a401..8ee0db1a8 100644
--- a/app/views/help/wiki_syntax/textile/bg/wiki_syntax_detailed_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/bg/wiki_syntax_detailed_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <title>RedmineWikiFormatting</title>
 <meta http-equiv="content-type" content="text/html; charset=utf-8" />
-<%= stylesheet_link_tag "wiki_syntax_detailed.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax_detailed" %>
 </head>
 
 <body>
diff --git a/app/views/help/wiki_syntax/textile/bg/wiki_syntax_textile.html.erb b/app/views/help/wiki_syntax/textile/bg/wiki_syntax_textile.html.erb
index 1a4d9fa54..683318c7a 100644
--- a/app/views/help/wiki_syntax/textile/bg/wiki_syntax_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/bg/wiki_syntax_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 <title>Wiki formatting</title>
-<%= stylesheet_link_tag "wiki_syntax.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax" %>
 </head>
 <body>
 
diff --git a/app/views/help/wiki_syntax/textile/ca/wiki_syntax_detailed_textile.html.erb b/app/views/help/wiki_syntax/textile/ca/wiki_syntax_detailed_textile.html.erb
index ff262a401..8ee0db1a8 100644
--- a/app/views/help/wiki_syntax/textile/ca/wiki_syntax_detailed_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/ca/wiki_syntax_detailed_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <title>RedmineWikiFormatting</title>
 <meta http-equiv="content-type" content="text/html; charset=utf-8" />
-<%= stylesheet_link_tag "wiki_syntax_detailed.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax_detailed" %>
 </head>
 
 <body>
diff --git a/app/views/help/wiki_syntax/textile/ca/wiki_syntax_textile.html.erb b/app/views/help/wiki_syntax/textile/ca/wiki_syntax_textile.html.erb
index 1f6959add..c347dde93 100644
--- a/app/views/help/wiki_syntax/textile/ca/wiki_syntax_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/ca/wiki_syntax_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 <title>Format de la Wiki</title>
-<%= stylesheet_link_tag "wiki_syntax.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax" %>
 </head>
 <body>
 
diff --git a/app/views/help/wiki_syntax/textile/cs/wiki_syntax_detailed_textile.html.erb b/app/views/help/wiki_syntax/textile/cs/wiki_syntax_detailed_textile.html.erb
index 80e92fb5a..8d525fb12 100644
--- a/app/views/help/wiki_syntax/textile/cs/wiki_syntax_detailed_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/cs/wiki_syntax_detailed_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <title>Formátování Wiki v Redminu</title>
 <meta http-equiv="content-type" content="text/html; charset=utf-8" />
-<%= stylesheet_link_tag "wiki_syntax_detailed.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax_detailed" %>
 </head>
 
 <body>
diff --git a/app/views/help/wiki_syntax/textile/cs/wiki_syntax_textile.html.erb b/app/views/help/wiki_syntax/textile/cs/wiki_syntax_textile.html.erb
index 9d724c45d..bb9157d94 100644
--- a/app/views/help/wiki_syntax/textile/cs/wiki_syntax_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/cs/wiki_syntax_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 <title>Wiki formátování</title>
-<%= stylesheet_link_tag "wiki_syntax.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax" %>
 </head>
 <body>
 
diff --git a/app/views/help/wiki_syntax/textile/de/wiki_syntax_detailed_textile.html.erb b/app/views/help/wiki_syntax/textile/de/wiki_syntax_detailed_textile.html.erb
index c060bb4ce..7c2457386 100644
--- a/app/views/help/wiki_syntax/textile/de/wiki_syntax_detailed_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/de/wiki_syntax_detailed_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <title>Redmine Wiki-Formatierung (Textile) detailliert</title>
 <meta http-equiv="content-type" content="text/html; charset=utf-8" />
-<%= stylesheet_link_tag "wiki_syntax_detailed.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax_detailed" %>
 </head>
 
 <body>
diff --git a/app/views/help/wiki_syntax/textile/de/wiki_syntax_textile.html.erb b/app/views/help/wiki_syntax/textile/de/wiki_syntax_textile.html.erb
index 989810c22..7f088baf0 100644
--- a/app/views/help/wiki_syntax/textile/de/wiki_syntax_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/de/wiki_syntax_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 <title>Wikiformatierung</title>
-<%= stylesheet_link_tag "wiki_syntax.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax" %>
 </head>
 <body>
 
diff --git a/app/views/help/wiki_syntax/textile/en/wiki_syntax_detailed_textile.html.erb b/app/views/help/wiki_syntax/textile/en/wiki_syntax_detailed_textile.html.erb
index ff262a401..8ee0db1a8 100644
--- a/app/views/help/wiki_syntax/textile/en/wiki_syntax_detailed_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/en/wiki_syntax_detailed_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <title>RedmineWikiFormatting</title>
 <meta http-equiv="content-type" content="text/html; charset=utf-8" />
-<%= stylesheet_link_tag "wiki_syntax_detailed.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax_detailed" %>
 </head>
 
 <body>
diff --git a/app/views/help/wiki_syntax/textile/en/wiki_syntax_textile.html.erb b/app/views/help/wiki_syntax/textile/en/wiki_syntax_textile.html.erb
index f02d5ac45..1c5962e07 100644
--- a/app/views/help/wiki_syntax/textile/en/wiki_syntax_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/en/wiki_syntax_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 <title>Wiki formatting</title>
-<%= stylesheet_link_tag "wiki_syntax.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax" %>
 </head>
 <body>
 
diff --git a/app/views/help/wiki_syntax/textile/es-pa/wiki_syntax_detailed_textile.html.erb b/app/views/help/wiki_syntax/textile/es-pa/wiki_syntax_detailed_textile.html.erb
index ff262a401..8ee0db1a8 100644
--- a/app/views/help/wiki_syntax/textile/es-pa/wiki_syntax_detailed_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/es-pa/wiki_syntax_detailed_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <title>RedmineWikiFormatting</title>
 <meta http-equiv="content-type" content="text/html; charset=utf-8" />
-<%= stylesheet_link_tag "wiki_syntax_detailed.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax_detailed" %>
 </head>
 
 <body>
diff --git a/app/views/help/wiki_syntax/textile/es-pa/wiki_syntax_textile.html.erb b/app/views/help/wiki_syntax/textile/es-pa/wiki_syntax_textile.html.erb
index 82f636b1a..0d1a15f3c 100644
--- a/app/views/help/wiki_syntax/textile/es-pa/wiki_syntax_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/es-pa/wiki_syntax_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 <title>Formato de la Wiki</title>
-<%= stylesheet_link_tag "wiki_syntax.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax" %>
 </head>
 <body>
 
diff --git a/app/views/help/wiki_syntax/textile/es/wiki_syntax_detailed_textile.html.erb b/app/views/help/wiki_syntax/textile/es/wiki_syntax_detailed_textile.html.erb
index ff262a401..8ee0db1a8 100644
--- a/app/views/help/wiki_syntax/textile/es/wiki_syntax_detailed_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/es/wiki_syntax_detailed_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <title>RedmineWikiFormatting</title>
 <meta http-equiv="content-type" content="text/html; charset=utf-8" />
-<%= stylesheet_link_tag "wiki_syntax_detailed.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax_detailed" %>
 </head>
 
 <body>
diff --git a/app/views/help/wiki_syntax/textile/es/wiki_syntax_textile.html.erb b/app/views/help/wiki_syntax/textile/es/wiki_syntax_textile.html.erb
index 82f636b1a..0d1a15f3c 100644
--- a/app/views/help/wiki_syntax/textile/es/wiki_syntax_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/es/wiki_syntax_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 <title>Formato de la Wiki</title>
-<%= stylesheet_link_tag "wiki_syntax.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax" %>
 </head>
 <body>
 
diff --git a/app/views/help/wiki_syntax/textile/fr/wiki_syntax_detailed_textile.html.erb b/app/views/help/wiki_syntax/textile/fr/wiki_syntax_detailed_textile.html.erb
index b4d75a0bb..4c8ccd606 100644
--- a/app/views/help/wiki_syntax/textile/fr/wiki_syntax_detailed_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/fr/wiki_syntax_detailed_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <title>RedmineWikiFormatting</title>
 <meta http-equiv="content-type" content="text/html; charset=utf-8" />
-<%= stylesheet_link_tag "wiki_syntax_detailed.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax_detailed" %>
 </head>
 
 <body>
diff --git a/app/views/help/wiki_syntax/textile/fr/wiki_syntax_textile.html.erb b/app/views/help/wiki_syntax/textile/fr/wiki_syntax_textile.html.erb
index ffab9638b..d57be064b 100644
--- a/app/views/help/wiki_syntax/textile/fr/wiki_syntax_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/fr/wiki_syntax_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 <title>Wiki formatting</title>
-<%= stylesheet_link_tag "wiki_syntax.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax" %>
 </head>
 <body>
 
diff --git a/app/views/help/wiki_syntax/textile/gl/wiki_syntax_detailed_textile.html.erb b/app/views/help/wiki_syntax/textile/gl/wiki_syntax_detailed_textile.html.erb
index 5c1555102..19597e52c 100644
--- a/app/views/help/wiki_syntax/textile/gl/wiki_syntax_detailed_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/gl/wiki_syntax_detailed_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <title>RedmineWikiFormatting</title>
 <meta http-equiv="content-type" content="text/html; charset=utf-8" />
-<%= stylesheet_link_tag "wiki_syntax_detailed.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax_detailed" %>
 </head>
 
 <body>
diff --git a/app/views/help/wiki_syntax/textile/gl/wiki_syntax_textile.html.erb b/app/views/help/wiki_syntax/textile/gl/wiki_syntax_textile.html.erb
index ae96e151e..68767abfb 100644
--- a/app/views/help/wiki_syntax/textile/gl/wiki_syntax_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/gl/wiki_syntax_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 <title>Wiki formatting</title>
-<%= stylesheet_link_tag "wiki_syntax.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax" %>
 </head>
 <body>
 
diff --git a/app/views/help/wiki_syntax/textile/ja/wiki_syntax_detailed_textile.html.erb b/app/views/help/wiki_syntax/textile/ja/wiki_syntax_detailed_textile.html.erb
index 5a6008c89..bad25f679 100644
--- a/app/views/help/wiki_syntax/textile/ja/wiki_syntax_detailed_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/ja/wiki_syntax_detailed_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <title>RedmineWikiFormatting</title>
 <meta http-equiv="content-type" content="text/html; charset=utf-8" />
-<%= stylesheet_link_tag "wiki_syntax_detailed.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax_detailed" %>
 </head>
 
 <body>
diff --git a/app/views/help/wiki_syntax/textile/ja/wiki_syntax_textile.html.erb b/app/views/help/wiki_syntax/textile/ja/wiki_syntax_textile.html.erb
index 35cbaf948..c93a6bad0 100644
--- a/app/views/help/wiki_syntax/textile/ja/wiki_syntax_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/ja/wiki_syntax_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 <title>Wiki formatting</title>
-<%= stylesheet_link_tag "wiki_syntax.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax" %>
 </head>
 <body>
 
diff --git a/app/views/help/wiki_syntax/textile/ko/wiki_syntax_detailed_textile.html.erb b/app/views/help/wiki_syntax/textile/ko/wiki_syntax_detailed_textile.html.erb
index ff262a401..8ee0db1a8 100644
--- a/app/views/help/wiki_syntax/textile/ko/wiki_syntax_detailed_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/ko/wiki_syntax_detailed_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <title>RedmineWikiFormatting</title>
 <meta http-equiv="content-type" content="text/html; charset=utf-8" />
-<%= stylesheet_link_tag "wiki_syntax_detailed.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax_detailed" %>
 </head>
 
 <body>
diff --git a/app/views/help/wiki_syntax/textile/ko/wiki_syntax_textile.html.erb b/app/views/help/wiki_syntax/textile/ko/wiki_syntax_textile.html.erb
index 56c6e727c..291dd48a0 100644
--- a/app/views/help/wiki_syntax/textile/ko/wiki_syntax_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/ko/wiki_syntax_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 <title>Wiki formatting</title>
-<%= stylesheet_link_tag "wiki_syntax.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax" %>
 </head>
 <body>
 
diff --git a/app/views/help/wiki_syntax/textile/lt/wiki_syntax_detailed_textile.html.erb b/app/views/help/wiki_syntax/textile/lt/wiki_syntax_detailed_textile.html.erb
index 06ca1d4ce..5df80521a 100644
--- a/app/views/help/wiki_syntax/textile/lt/wiki_syntax_detailed_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/lt/wiki_syntax_detailed_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <title>RedmineWikiFormatting</title>
 <meta http-equiv="content-type" content="text/html; charset=utf-8" />
-<%= stylesheet_link_tag "wiki_syntax_detailed.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax_detailed" %>
 </head>
 
 <body>
diff --git a/app/views/help/wiki_syntax/textile/lt/wiki_syntax_textile.html.erb b/app/views/help/wiki_syntax/textile/lt/wiki_syntax_textile.html.erb
index f02d5ac45..1c5962e07 100644
--- a/app/views/help/wiki_syntax/textile/lt/wiki_syntax_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/lt/wiki_syntax_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 <title>Wiki formatting</title>
-<%= stylesheet_link_tag "wiki_syntax.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax" %>
 </head>
 <body>
 
diff --git a/app/views/help/wiki_syntax/textile/nl/wiki_syntax_detailed_textile.html.erb b/app/views/help/wiki_syntax/textile/nl/wiki_syntax_detailed_textile.html.erb
index ff262a401..8ee0db1a8 100644
--- a/app/views/help/wiki_syntax/textile/nl/wiki_syntax_detailed_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/nl/wiki_syntax_detailed_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <title>RedmineWikiFormatting</title>
 <meta http-equiv="content-type" content="text/html; charset=utf-8" />
-<%= stylesheet_link_tag "wiki_syntax_detailed.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax_detailed" %>
 </head>
 
 <body>
diff --git a/app/views/help/wiki_syntax/textile/nl/wiki_syntax_textile.html.erb b/app/views/help/wiki_syntax/textile/nl/wiki_syntax_textile.html.erb
index 176a14d2a..c115f956a 100644
--- a/app/views/help/wiki_syntax/textile/nl/wiki_syntax_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/nl/wiki_syntax_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 <title>Wiki formatting</title>
-<%= stylesheet_link_tag "wiki_syntax.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax" %>
 </head>
 <body>
 
diff --git a/app/views/help/wiki_syntax/textile/pt-br/wiki_syntax_detailed_textile.html.erb b/app/views/help/wiki_syntax/textile/pt-br/wiki_syntax_detailed_textile.html.erb
index ff262a401..8ee0db1a8 100644
--- a/app/views/help/wiki_syntax/textile/pt-br/wiki_syntax_detailed_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/pt-br/wiki_syntax_detailed_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <title>RedmineWikiFormatting</title>
 <meta http-equiv="content-type" content="text/html; charset=utf-8" />
-<%= stylesheet_link_tag "wiki_syntax_detailed.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax_detailed" %>
 </head>
 
 <body>
diff --git a/app/views/help/wiki_syntax/textile/pt-br/wiki_syntax_textile.html.erb b/app/views/help/wiki_syntax/textile/pt-br/wiki_syntax_textile.html.erb
index 437fc0ec5..5e4899851 100644
--- a/app/views/help/wiki_syntax/textile/pt-br/wiki_syntax_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/pt-br/wiki_syntax_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 <title>Formata&ccedil;&atilde;o Wiki</title>
-<%= stylesheet_link_tag "wiki_syntax.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax" %>
 </head>
 <body>
 
diff --git a/app/views/help/wiki_syntax/textile/ru/wiki_syntax_detailed_textile.html.erb b/app/views/help/wiki_syntax/textile/ru/wiki_syntax_detailed_textile.html.erb
index 2baf32b79..c31df4437 100644
--- a/app/views/help/wiki_syntax/textile/ru/wiki_syntax_detailed_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/ru/wiki_syntax_detailed_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <title>Форматирование Wiki Redmine</title>
 <meta http-equiv="content-type" content="text/html; charset=utf-8" />
-<%= stylesheet_link_tag "wiki_syntax_detailed.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax_detailed" %>
 </head>
 
 <body>
diff --git a/app/views/help/wiki_syntax/textile/ru/wiki_syntax_textile.html.erb b/app/views/help/wiki_syntax/textile/ru/wiki_syntax_textile.html.erb
index b06d5abe9..28bceff44 100644
--- a/app/views/help/wiki_syntax/textile/ru/wiki_syntax_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/ru/wiki_syntax_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 <title>Форматирование Wiki</title>
-<%= stylesheet_link_tag "wiki_syntax.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax" %>
 </head>
 <body>
 
diff --git a/app/views/help/wiki_syntax/textile/ta-in/wiki_syntax_detailed_textile.html.erb b/app/views/help/wiki_syntax/textile/ta-in/wiki_syntax_detailed_textile.html.erb
index da1f15b8d..12cfbecfb 100644
--- a/app/views/help/wiki_syntax/textile/ta-in/wiki_syntax_detailed_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/ta-in/wiki_syntax_detailed_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <title>RedmineWikiவடிவமைத்தல்</title>
 <meta http-equiv="content-type" content="text/html; charset=utf-8" />
-<%= stylesheet_link_tag "wiki_syntax_detailed.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax_detailed" %>
 </head>
 
 <body>
diff --git a/app/views/help/wiki_syntax/textile/ta-in/wiki_syntax_textile.html.erb b/app/views/help/wiki_syntax/textile/ta-in/wiki_syntax_textile.html.erb
index 3e7cae40b..7587d51e5 100644
--- a/app/views/help/wiki_syntax/textile/ta-in/wiki_syntax_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/ta-in/wiki_syntax_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 <title>Wiki formatting</title>
-<%= stylesheet_link_tag "wiki_syntax.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax" %>
 </head>
 <body>
 
diff --git a/app/views/help/wiki_syntax/textile/uk/wiki_syntax_detailed_textile.html.erb b/app/views/help/wiki_syntax/textile/uk/wiki_syntax_detailed_textile.html.erb
index 07bf6eda5..4c45f5c7f 100644
--- a/app/views/help/wiki_syntax/textile/uk/wiki_syntax_detailed_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/uk/wiki_syntax_detailed_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <title>Redmine - форматування вікі сторінок</title>
 <meta http-equiv="content-type" content="text/html; charset=utf-8" />
-<%= stylesheet_link_tag "wiki_syntax_detailed.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax_detailed" %>
 </head>
 
 <body>
diff --git a/app/views/help/wiki_syntax/textile/uk/wiki_syntax_textile.html.erb b/app/views/help/wiki_syntax/textile/uk/wiki_syntax_textile.html.erb
index 2c791496a..7e2359a68 100644
--- a/app/views/help/wiki_syntax/textile/uk/wiki_syntax_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/uk/wiki_syntax_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 <title>Вікі синтаксис</title>
-<%= stylesheet_link_tag "wiki_syntax.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax" %>
 </head>
 <body>
 
diff --git a/app/views/help/wiki_syntax/textile/zh-tw/wiki_syntax_detailed_textile.html.erb b/app/views/help/wiki_syntax/textile/zh-tw/wiki_syntax_detailed_textile.html.erb
index e0c58b501..8577a5bd8 100644
--- a/app/views/help/wiki_syntax/textile/zh-tw/wiki_syntax_detailed_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/zh-tw/wiki_syntax_detailed_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <title>RedmineWikiFormatting</title>
 <meta http-equiv="content-type" content="text/html; charset=utf-8" />
-<%= stylesheet_link_tag "wiki_syntax_detailed.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax_detailed" %>
 </head>
 
 <body>
diff --git a/app/views/help/wiki_syntax/textile/zh-tw/wiki_syntax_textile.html.erb b/app/views/help/wiki_syntax/textile/zh-tw/wiki_syntax_textile.html.erb
index 1f5be349f..37ae0281b 100644
--- a/app/views/help/wiki_syntax/textile/zh-tw/wiki_syntax_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/zh-tw/wiki_syntax_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 <title>Wiki 格式設定</title>
-<%= stylesheet_link_tag "wiki_syntax.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax" %>
 </head>
 <body>
 
diff --git a/app/views/help/wiki_syntax/textile/zh/wiki_syntax_detailed_textile.html.erb b/app/views/help/wiki_syntax/textile/zh/wiki_syntax_detailed_textile.html.erb
index e3291340f..e7bd70a39 100644
--- a/app/views/help/wiki_syntax/textile/zh/wiki_syntax_detailed_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/zh/wiki_syntax_detailed_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <title>RedmineWikiFormatting</title>
 <meta http-equiv="content-type" content="text/html; charset=utf-8" />
-<%= stylesheet_link_tag "wiki_syntax_detailed.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax_detailed" %>
 </head>
 
 <body>
diff --git a/app/views/help/wiki_syntax/textile/zh/wiki_syntax_textile.html.erb b/app/views/help/wiki_syntax/textile/zh/wiki_syntax_textile.html.erb
index a1cde351f..691794679 100644
--- a/app/views/help/wiki_syntax/textile/zh/wiki_syntax_textile.html.erb
+++ b/app/views/help/wiki_syntax/textile/zh/wiki_syntax_textile.html.erb
@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 <title>Wiki formatting</title>
-<%= stylesheet_link_tag "wiki_syntax.css" %>
+<%= heads_for_wiki_syntax "wiki_syntax" %>
 </head>
 <body>
 
diff --git a/test/functional/help_controller_test.rb b/test/functional/help_controller_test.rb
index 0aeaba5da..141395974 100644
--- a/test/functional/help_controller_test.rb
+++ b/test/functional/help_controller_test.rb
@@ -109,4 +109,22 @@ class HelpControllerTest < Redmine::ControllerTest
       assert_select '>td:nth-of-type(2)', :text => /\[aliases: rb\]/
     end
   end
+
+  def test_get_help_wiki_syntax_should_include_dark_color_scheme
+    [{}, {:type => 'detailed'}].each do |params|
+      get :show_wiki_syntax, :params => params
+
+      assert_response :success
+      assert_select 'meta[name=color-scheme][content=?]', 'light dark'
+      assert_select "link[rel=stylesheet][media=?]:match('href', ?)",
+                    'screen and (prefers-color-scheme: dark)', %r{/dark(-\w+)?\.css}
+    end
+  end
+
+  def test_get_help_code_highlighting_should_include_dark_color_scheme
+    get :show_code_highlighting
+
+    assert_response :success
+    assert_select "link[rel=stylesheet]:match('href', ?)", %r{/dark(-\w+)?\.css}
+  end
 end
-- 
2.43.0