Another report from Znuny: https://ticket.wikimedia.org/otrs/index.pl?Action=AgentTicketZoom;TicketID=11946322

Some math formula use the template {{Equation box 1}} and specify a white background. In
Wikipedia App with dark mode on, the formula text is shown as white (like other text
color), however, the equation box is still shown as white background, which make it
unreadable. I believe the background in this case, should be inverted so
readability can be improved.

Another report from an Android user: Your app is excellent, thanks for your work. I have had this issue on several pages using the android app. On some pages in the gray and black themes some math equations show up in black instead of inverted color font. An example of such a page is the page for "Dynkin system". In this page the (what would be math mode in LaTeX) centered equations in the section "Application to probability distributions" show up as black, so they are invisible in the black theme and barely visible in the gray theme.

Report from an android user: >Dark mode is unusable because <math style="block"> does not display. Equations central to the articles disappear.
Article - https://en.wikipedia.org/wiki/Antilinear_map

Another report from Znuny:

Hey I’ve been having some problems with Wikipedia. Some pages do not display the math that is intended to be displayed. It’s not just a problem with one article, there are others with the same issue. However, there are also pages that do display the math. I’ll attach some screenshots. Appreciate any help.

Version: WikipediaApp/6.8.1.1815 (iOS 13.6; Phone)

Report from android user:

Your app is no longer functional in that where mathematical equations should be there are just blank spaces. This has been that way for a long time and you have done nothing about it. I want nothing more to do with such incompetence and am signing out of my account and permanently deleting your app.

Report from an iOS user:

When there is some math latex in a frame, using dark mode will turn the text white without changing the background color, so it becomes impossible to see it. The same issue can happen in sheets with colored cells. Here is an example where its still possible to read but the contrast is really bad. Thanks for your work! Thats a great app :)

Thank you for your clarification on this issue. However, I apparently was
not clear in my previous post. I used to be able to see the equations
perfectly clear on all searches before a previous update. Now I can see
less visible images on some and not at all on others. To show you I took a
screen shot of two different sites. Why this happened I don't know. To view
Wikipedia in dark mode I now have to turn off dark mode and invert color,
which is inconvenient to say the least.

What I find puzzling about the current black-on-black rendering issues is that according to the history of T254545 there was a time in mid-2020 when the issue was fixed. Is there some archived version of the html output and, more importantly, the relevant codebase at the time to check for changes that were made prior to and after the apparent fix? The link posted in T254545 (this link to a mobile-html page) currently renders with the issue not resolved.

Another report from Znuny on Android

How to reproduce: Search english wiki for „action physics“ and choose entry titled „physical wuantity of dimension energy*time. Scroll down to „action (functional)“ in section „Action in Classical Physics“

Now turn dark mode on and off. The formula: S[q(t)] = … before the sentence... where the endpoints of the evolution… is not visible in dark mode. Please see the attached video. Same is true for other formula. Version: WikipediaApp/6.8.2.1868 (iOS 15.3.1; Phone) Mit freundlichem Gruß - Christoph Leser

Note - Could not attach user's video, wrong format

Report from iOS user -

Math and math diagrams do not render correctly in dark mode. This is an issue that has existed for several months and is quite frustrating. Here is a screenshot for example. Version: WikipediaApp/6.8.2.1868 (iOS 15.4.1; Tablet) - Best regards, Andrew Paul

Report from an iOS user:

Equations rendered in dark mode are illegible, as the font is still black, and the separation bar in fractions is difficult to see. E.g on the enthalpy article:

User feedback by email on May 23, 2022:

In dark mode, mathematical formulas are invisible as they are black text on transparent background.

User feedback by email on May 26, 2022:

Hey there!
I just wanted to report a bug that is disturbing me for some time. Some articles (not all), while using dark mode, do not change the color of the math in them (an image is attached).

User feedback by email on May 30, 2022:

Please fix Offline Wikipedia's display of LaTeX. It displays HTML formulas finely but it breaks when displaying LaTeX formulas. See picture attached to see what I mean

The article shown in the screenshot is "De Rham Cohomology", fourth paragraph of the "Definition" section: https://en.wikipedia.org/wiki/De_Rham_cohomology?wprov=sfla1.

But let me just reiterate that the problem is not particular to this one article, it happens to EVERY SINGLE article with LaTeX in it. Also this issue is not particular to my current device, all other phones where I've had Wikipedia installed had this very same issue.

Report from a user on Znuny: https://ticket.wikimedia.org/otrs/index.pl?Action=AgentTicketZoom;TicketID=12207710

Math equations are not visible in dark mode. I have reported this problem previously but received no response. This is an issue on the iOS app as well.

Report from a user on Android -

In the Wikipedia app for Android, math equations have black text, and thus do not display visibly in dark mode. Could you please submit a ticket to fix this? I greatly enjoy using the Wikipedia app and it would improve my experience if I could read math equations in the app using dark mode too.