diff --git a/calibre-plugin/plugin-defaults.ini b/calibre-plugin/plugin-defaults.ini
index a1e99c94..669a0ad3 100644
--- a/calibre-plugin/plugin-defaults.ini
+++ b/calibre-plugin/plugin-defaults.ini
@@ -956,7 +956,8 @@ use_threadmark_wordcounts:true
 
 ## When reveal_invisible_text is set true, adapter will search for
 ## <span style="color:transparent"> tags and remove the style
-## attribute.
+## attribute.  Also adds class="invisible_text" for custom CSS
+## styling, see invisible_text add_to_output_css example below.
 #reveal_invisible_text:false
 
 [base_xenforoforum:epub]
@@ -968,6 +969,16 @@ use_threadmark_wordcounts:true
 #add_to_output_css:
 # .bbCodeSpoilerContainer { border: 1px solid black; padding: 2px; }
 
+## When reveal_invisible_text:true, you can style the class
+## invisible_text as you like for forum "invisible text". See
+## reveal_invisible_text above.  This is just one example.  Note that
+## if you also use the add_to_output_css example above for
+## bbCodeSpoilerContainer spoilers, you need to combine the CSS lines
+## for both under one add_to_output_css setting, with a space leading
+## each CSS line.
+#add_to_output_css:
+# .invisible_text { color:gray; }
+
 [base_xenforo2forum]
 ## [base_xenforoforum] also applied, but [base_xenforo2forum] takes
 ## precedence.
diff --git a/fanficfare/adapters/base_xenforoforum_adapter.py b/fanficfare/adapters/base_xenforoforum_adapter.py
index ec139020..828c0ed0 100644
--- a/fanficfare/adapters/base_xenforoforum_adapter.py
+++ b/fanficfare/adapters/base_xenforoforum_adapter.py
@@ -788,9 +788,14 @@ class BaseXenForoForumAdapter(BaseSiteAdapter):
 
     def _do_utf8FromSoup(self,url,soup,fetch=None,allow_replace_br_with_p=True):
         if self.getConfig('reveal_invisible_text'):
-            ## when set, remove style='color:transparent'.
+            ## when set, remove style='color:transparent' and add
+            ## class="invisible_text"
             for span in soup.find_all('span',style='color:transparent'):
                 del span['style']
+                if not span.has_attr('class'):
+                    # give it a class list if it doesn't have one.
+                    span['class']=[]
+                span['class'].append("invisible_text")
         if self.getConfig('replace_failed_smilies_with_alt_text'):
             for img in soup.find_all('img',src=re.compile(r'(^data:image|(failedtoload|clear.png)$)')):
                 # logger.debug("replace_failed_smilies_with_alt_text img: %s"%img)
diff --git a/fanficfare/defaults.ini b/fanficfare/defaults.ini
index 88659dd9..ac5654e3 100644
--- a/fanficfare/defaults.ini
+++ b/fanficfare/defaults.ini
@@ -974,7 +974,8 @@ use_threadmark_wordcounts:true
 
 ## When reveal_invisible_text is set true, adapter will search for
 ## <span style="color:transparent"> tags and remove the style
-## attribute.
+## attribute.  Also adds class="invisible_text" for custom CSS
+## styling, see invisible_text add_to_output_css example below.
 #reveal_invisible_text:false
 
 [base_xenforoforum:epub]
@@ -986,6 +987,16 @@ use_threadmark_wordcounts:true
 #add_to_output_css:
 # .bbCodeSpoilerContainer { border: 1px solid black; padding: 2px; }
 
+## When reveal_invisible_text:true, you can style the class
+## invisible_text as you like for forum "invisible text". See
+## reveal_invisible_text above.  This is just one example.  Note that
+## if you also use the add_to_output_css example above for
+## bbCodeSpoilerContainer spoilers, you need to combine the CSS lines
+## for both under one add_to_output_css setting, with a space leading
+## each CSS line.
+#add_to_output_css:
+# .invisible_text { color:gray; }
+
 [base_xenforo2forum]
 ## [base_xenforoforum] also applied, but [base_xenforo2forum] takes
 ## precedence.