Developer reply by Lab5
Rated 1 out of 5 stars
I strongly agree with Sensor, even when de add would become available at a small cost I would be more than happy to pay a few $ for it!
Miss my coloured folders... :-(
While the new version on thunderbird.net is still in review and waiting for approval from the Thunderbird team, so it can go public here on this page too.
Download here manually : https://lab5.ch/colored-folders
To create your own collections, you must have a Mozilla Add-ons account.