This bug happens also with the default Ambiance theme on Ubuntu 17.10. See attached screenshot.
** Attachment added: "thunderbird_low_contrast.png" https://bugs.launchpad.net/ubuntu/+source/thunderbird/+bug/1710059/+attachment/5070119/+files/thunderbird_low_contrast.png -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1710059 Title: Theming issue when searching in Thunderbird To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-mate/+bug/1710059/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs