From 21f5069e48d92af17a0b8b805342e956282e19ac Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hugo=20H=C3=B6rnquist?= <hugo@lysator.liu.se>
Date: Sat, 26 Jan 2019 10:29:29 +0100
Subject: [PATCH 1/4] Code-blocks auto-color.

---
 autoload/vimwiki/html.vim | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/autoload/vimwiki/html.vim b/autoload/vimwiki/html.vim
index ba2cc4c..243189a 100644
--- a/autoload/vimwiki/html.vim
+++ b/autoload/vimwiki/html.vim
@@ -344,7 +344,17 @@ endfunction
 
 
 function! s:tag_code(value)
-  return '<code>'.s:safe_html_preformatted(s:mid(a:value, 1)).'</code>'
+  let l:retstr = '<code'
+
+  let l:str = s:mid(a:value, 1)
+  let l:match = match(l:str, '^#[a-fA-F0-9]\{6\}$')
+
+  if l:match != -1
+    let l:retstr .= " style='background-color: " . l:str . ";'"
+  endif
+
+  let l:retstr .= '>'.s:safe_html_preformatted(l:str).'</code>'
+  return l:retstr
 endfunction
 
 

From 08ec02a7554e9981967f0a4443ea310b7fbdccd8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hugo=20H=C3=B6rnquist?= <hugo@lysator.liu.se>
Date: Tue, 19 Feb 2019 21:04:57 +0100
Subject: [PATCH 2/4] Alternative where text color is inverse of background.

---
 autoload/vimwiki/html.vim | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/autoload/vimwiki/html.vim b/autoload/vimwiki/html.vim
index 243189a..b9ed95c 100644
--- a/autoload/vimwiki/html.vim
+++ b/autoload/vimwiki/html.vim
@@ -349,8 +349,12 @@ function! s:tag_code(value)
   let l:str = s:mid(a:value, 1)
   let l:match = match(l:str, '^#[a-fA-F0-9]\{6\}$')
 
+
   if l:match != -1
-    let l:retstr .= " style='background-color: " . l:str . ";'"
+    let l:inv_color = 0xFFFFFF - eval("0x" . l:str[1:])
+
+    let l:retstr .= printf(" style='background-color: %s; color: #%x;'",
+          \ l:str, l:inv_color)
   endif
 
   let l:retstr .= '>'.s:safe_html_preformatted(l:str).'</code>'

From 2f87f92060a154f71416e8ac84dc48d96c03dc4e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hugo=20H=C3=B6rnquist?= <hugo@lysator.liu.se>
Date: Sun, 17 Mar 2019 22:40:34 +0100
Subject: [PATCH 3/4] Better foreground for colorcodes.

---
 autoload/vimwiki/html.vim | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/autoload/vimwiki/html.vim b/autoload/vimwiki/html.vim
index b9ed95c..0ad9ea4 100644
--- a/autoload/vimwiki/html.vim
+++ b/autoload/vimwiki/html.vim
@@ -349,12 +349,18 @@ function! s:tag_code(value)
   let l:str = s:mid(a:value, 1)
   let l:match = match(l:str, '^#[a-fA-F0-9]\{6\}$')
 
-
   if l:match != -1
-    let l:inv_color = 0xFFFFFF - eval("0x" . l:str[1:])
+    let l:r = eval("0x".l:str[1:2])
+    let l:g = eval("0x".l:str[3:4])
+    let l:b = eval("0x".l:str[5:6])
 
-    let l:retstr .= printf(" style='background-color: %s; color: #%x;'",
-          \ l:str, l:inv_color)
+    let l:fg_color =
+          \ (((0.299 * r + 0.587 * g + 0.114 * b) / 0xFF) > 0.5)
+          \ ? "black" : "white"
+
+    let l:retstr .=
+          \ " style='background-color:" . l:str .
+          \ ";color:" . l:fg_color . ";'"
   endif
 
   let l:retstr .= '>'.s:safe_html_preformatted(l:str).'</code>'

From da52523710af2f6252eae8fe02ff147e7d498d67 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hugo=20H=C3=B6rnquist?= <hugo@lysator.liu.se>
Date: Sun, 17 Mar 2019 22:50:56 +0100
Subject: [PATCH 4/4] Add documentation for colorcodes.

---
 doc/vimwiki.txt | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/doc/vimwiki.txt b/doc/vimwiki.txt
index 4f935e5..457b1f3 100644
--- a/doc/vimwiki.txt
+++ b/doc/vimwiki.txt
@@ -880,6 +880,12 @@ is decorated: >
 Furthermore, there are a number of words which are highlighted extra flashy:
 TODO, DONE, STARTED, FIXME, FIXED, XXX.
 
+When rendered as HTML, code blocks containing only a hash prefixed 6 digit hex
+number will be colored as themselves.  For example >
+ `#ffe119`
+Becomes >
+ <code style='background-color:#ffe119;color:black;'>#ffe119</code>
+
 ------------------------------------------------------------------------------
 5.2. Links                                              *vimwiki-syntax-links*