diff --git a/news/248.bugfix b/news/248.bugfix
new file mode 100644
index 00000000..1feb6363
--- /dev/null
+++ b/news/248.bugfix
@@ -0,0 +1 @@
+Update the link and label under Site Setup > Theming > Advanced settings > Custom Styles to Theming of Classic UI at https://6.docs.plone.org/classic-ui/theming/index.html. @stevepiercy
diff --git a/src/plone/app/theming/browser/controlpanel.pt b/src/plone/app/theming/browser/controlpanel.pt
index 382f638b..621c8d5d 100644
--- a/src/plone/app/theming/browser/controlpanel.pt
+++ b/src/plone/app/theming/browser/controlpanel.pt
@@ -725,10 +725,10 @@
                             Define your own custom CSS in the field below. This is a good place for quick customizations of things like colors and the toolbar. Definitions here will override previously defined CSS of Plone. Please use this only for small customizations, as it is hard to keep track of changes here. For bigger changes you most likely want to customize a full theme and make your changes there.
                         </div>
                         <div class="theming_doc_link">
-                          <p><a href="https://docs.plone.org/adapt-and-extend/theming"
+                          <p><a href="https://6.docs.plone.org/classic-ui/theming/index.html"
                                target="_blank"
                                i18n:translate="label_theming_doc_link"
-                            >Theming documentation</a></p>
+                            >Theming of Classic UI documentation</a></p>
                         </div>
 
                         <div class="errorMessage"