Comment 6 for bug 1347305

Thank you for pointing to the bugzilla report. By now, there has been quite some input over there and the developers have responded, too. Personal preferences for the "look" may vary. But to me, this is a usability issue: editable text fields should be recognisable as editable text fields. You can find the current discussion at
https://bugzilla.mozilla.org/show_bug.cgi?id=1042780
including this screenshot of Ubuntu 14.04 LTS with a "workaround" Thunderbird 31 compose window
https://bug1042780.bugzilla.mozilla.org/attachment.cgi?id=8467753