Allow any element to get this behavior with just a class.

website_mail_snippet_bg_color/views/snippets.xml

@@ -10,7 +10,9 @@
     <xpath expr="//div[@id='snippet_options']">
         <div
             data-snippet-option-id='bg_color_chooser'
-            data-selector="[data-oe-field='body_html'] > div, .oe_snippet_body"
+            data-selector="[data-oe-field='body_html'] > div,
+                           .oe_snippet_body,
+                           .bg_color_chooser"
             data-selector-siblings="[data-oe-field='body_html'] > *"
             data-selector-children="[data-oe-field='body_html']">
             <li>