marked how?

Hi Matt,

"marked" this way (see picture), thank you for the answer!

Alex

Unless you are using an add-on theme, I believe that that color is controlled by the operating system. On a Mac, it is called the "accent color" in system settings. I don't know what Windows calls it.

This is the one and only theme in my thunderbird-onstallation...

Thank you for trying to help me.

So it must be a Windows setting, not a Thunderbird setting.

Open Windows Settings, Personalization, Colours, Accent colour, change to Manual.

Hi sfhowes,

THANK YOU, THANK YOU, THANK YOU!

That was the solution. I think I have to change my OS to besafe from unwantes changes to my settings.

Alex