diff --git a/src/calibre/gui2/tweak_book/editor/syntax/html.py b/src/calibre/gui2/tweak_book/editor/syntax/html.py
index 39bca4e52e..e9e1ed3514 100644
--- a/src/calibre/gui2/tweak_book/editor/syntax/html.py
+++ b/src/calibre/gui2/tweak_book/editor/syntax/html.py
@@ -28,7 +28,7 @@ attribute_name_pat = re.compile(r'''[^%s"'/><=]+''' % space_chars)
 self_closing_pat = re.compile(r'/\s*>')
 unquoted_val_pat = re.compile(r'''[^%s'"=<>`]+''' % space_chars)
 cdata_close_pats = {x:re.compile(r'</%s' % x, flags=re.I) for x in cdata_tags}
-nbsp_pat = re.compile('[\xa0\u2011]+')  # non-breaking spaces and hyphens
+nbsp_pat = re.compile('[\xa0\u2000-\u200A\u202F\u205F\u3000\u2011-\u2015\uFE58\uFE63\uFF0D]+')  # special spaces and hyphens
 
 class State(object):
 
@@ -303,7 +303,7 @@ def create_formats(highlighter):
         'string': t['String'],
         'nsprefix': t['Constant'],
         'preproc': t['PreProc'],
-        'nbsp': t['CursorLine'],
+        'nbsp': t['SpecialCharacter'],
     }
     for name, msg in {
         '<': _('An unescaped < is not allowed. Replace it with &lt;'),
diff --git a/src/calibre/gui2/tweak_book/editor/themes.py b/src/calibre/gui2/tweak_book/editor/themes.py
index d213d6b78a..1c16ecea96 100644
--- a/src/calibre/gui2/tweak_book/editor/themes.py
+++ b/src/calibre/gui2/tweak_book/editor/themes.py
@@ -57,6 +57,7 @@ SOLARIZED = \
     Statement    fg={green} bold
     Keyword      fg={green}
     Special      fg={red}
+    SpecialCharacter bg={base02}
 
     Error        us=wave uc={red}
     Tooltip      fg=black bg=ffffed
@@ -94,6 +95,7 @@ THEMES = {
     Keyword      fg={keyword}
     Special      fg=e7f6da
     Error        us=wave uc=red
+    SpecialCharacter bg={cursor_loc}
 
     '''.format(
         cursor_loc='3d3d3d',
@@ -132,6 +134,7 @@ THEMES = {
     Statement    fg={keyword}
     Keyword      fg={keyword}
     Special      fg=70a0d0 italic
+    SpecialCharacter bg={cursor_loc}
     Error        us=wave uc=red
 
     '''.format(