Rated 5 out of 5 stars

by dreadnaut on Nov. 17, 2018 ·

I have used a custom version for a while, which add multiple border styles and fixes a couple of bugs.

To keep a version compatible with TB60 online, I have now released it as "BorderColors D".

https://addons.thunderbird.net/en-US/thunderbird/addon/bordercolors-d/

This user has a previous review of this add-on.