Rated 4 out of 5 stars

Nice concept. 1) I am not able to color the CC/BCC fields of the message pane. 2) When new mail enters the folder, the folder becomes bold but does not colors, unless I hover on it with the mouse. All "reinstates" are set. Use version 68.3 of TB.

This review is for a previous version of the add-on (13.0). 

1) The general idea is to highlight the account/identity that messages are sent from. So only the From email address and meesage Subject are colored.

2) This is a bug that was not spotted during the update for Thunderbird 68. A new version (13.1) of Account Colors, that fixes this problem, has been submitted to the Thunderbird team for review and release (which may take a week or more).