any help.... this problem is hard to work with as I use TB for my work!

You are talking about two diffenent things. One is the new mail notification. The other is the appearance of mail in the user interface.

The new mil notification sounds like it is working as advertised, offering a notification of new mail and changing on the next sync, probably because there is no mail in that one.

The second is a user interface issue that could have many causes.

The most common is mail being downloaded on another device such as a phone and marking the mail read on the server. Not much we can do there. As a mac user you probably also have an apple phone. They are notorious for such behavior.

The second is a theme issue. so restarting Thunderbird will add-ons disabled from the help menu will see normal colors displayed. If it is a theme, change themes or contact the theme author.

arghhhhhhhhh the mac I have just upgraded from is showing them as needed this new machine is therefore not highlighting them, quit TB on old machine and all good..... thanks Matt