Review for Colored Folders by Bor
Rated 5 out of 5 stars
" door Retief op jan 12, 2020 · permalink
I have used this add-on (previous version) for years. Love it! However, the latest version has a bug, at least in Thunderbird 68.4.1: The folders do not become colored until I drag the pointer across the folders; then they change to the colors I've assigned."
The same thing happens to me too.
To create your own collections, you must have a Mozilla Add-ons account.