Merge branch 'colorcodes' into 'dev'. Closes PR #616.

This colors all CSS color codes found alone in inline code blocks to the
color they mention.

autoload/vimwiki/html.vim

@@ -344,7 +344,27 @@ 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: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: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>'
+  return l:retstr
 endfunction