1651392 - Ubuntu 20 dark mode, Thunderbird rendering nearly-white text on white

Status: RESOLVED DUPLICATE of bug 1639249

(Thunderbird :: Theme, defect)

Description

[Julian Field]

Attachment: Email message that demonstrates the problem

+++ This bug was initially created as a clone of Bug #1651384 +++

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4103.116 Safari/537.36

Steps to reproduce:

Set Ubuntu desktop appearance to Dark mode.
Start Thunderbird.
View HTML email message (attached).

Actual results:

When the Mac is in Dark mode, the message is rendered with nearly-white text on a white background.

Expected results:

The message should have been rendered in nearly-white on black, or else black on white, so the text is legible.
When the Mac is in Light mode, the message is rendered legibly with either Thunderbird's supplied "Default" or "Dark" themes. This is how it (correctly) renders on Windows.
All tested on 2020-07-07 nightly build.
Attached are the email message itself so you can reproduce it, along with screenshots showing problem.

Comment 1

[Julian Field]

Attachment: Ubuntu-Dark-with-Tbird-Dark-theme.png

Message rendered illegibly in Ubuntu Dark mode.

Comment 2

[Julian Field]

Attachment: Ubuntu-Dark-with-Tbird-Default-theme.png

Message rendered illegibly in Ubuntu Dark mode.

Comment 3

[Julian Field]

Attachment: Ubuntu-Standard-with-Tbird-Dark-theme.png

Message rendered correctly in Ubuntu's Light mode.

Comment 4

[Julian Field]

Attachment: Ubuntu-Standard-with-Tbird-Default-theme.png

Message rendered correctly in Ubuntu's Light mode.

Comment 5

[Richard Marti (:Paenglab)]

The problem is, that the message author only sets the background colour and thinks the text colour will be black. But with the dark theme it will be inverted with white text colour.

It's bad HTML to define only one of the two colour pair (text colour/background colour) and suppose the other part will be what the think.