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All mails are shown in black and white.

Disabling the add-on again seemingly restores the coloring.

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Clarification

This behavior is not produced directly inflicted by the add-on.

The same behavior can also be re-produced by opening e.g. the Javascript Console, the Javascript Environment, Appointments or Reminders of the Lightning add-ons or other popup windows of other add-ons.

For all above cases it is irrelevant if the add-on Thunderbird Integration for Jira was installed or not respectively enabled or not.

but by a change in the Thundebird's own code.

It happened between Version 63 and 64; with all following versions showing this behaviour

The This behavior is controlled by the decorator of the main window of Thunderbird itself. As soon as loosing the focus a CSS rule is activated that has the described effect. You can click on the Thunderbird main window at any time, even when having popups opened to focus it again.

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We will try to investigate further and attempt to fix this but since Thunderbird 73 probably needs a completely new Webextension this might not be fixed anymore.

Workaround

Please enable the column "Tag" in your mailfolder(s) to show the named labels.

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