I'm trying to add colour/color buttons to Ckeditor on a new site. I've done it on a previous site using configuration option for the editor in Administer >> Display preferences, but either I have forgotten something or something has changed with an upgrade.
As described in How to restore the colour button in Ckeditor I add the Colorbutton plugin, but no buttons appear. The color group was already there but it remains empty. I can't see any options for adding or moving individual buttons (just hiding buttons or adding separators).
I've tried clearing caches, but as it doesn't show in the config screen I don't think that is relevant.
CiviCRM 5.15.1 and WordPress 5.3.1