Thanks for your reply cyberzork. Unfortunately this isn’t the issue I have, I don’t think I’ve explained very clearly.
I’m referring to the background of new/unread emails when shown in the Inbox or folder listing. Here’s an old thread explaining how to do it:
But changing the three properties mentioned doesn’t have any effect for me - the background and text colour don’t change at all. However all other properties I’ve edited in the theme editor do seem to work.
I’ve tried changing the theme back to the default and editing that, but nothing I do can make these three properties actually update the colours.
I’m wondering if this is a Mac-specific issue?