User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:91.0) Gecko/20100101 Firefox/91.0

Steps to reproduce:

Firefox 91.0 does not work with Canva: Firefox blocks out background images in designs. And, all the checkboxes on every page have white text so I have no idea whether they are clicked or not. Example: checking the box to accept terms/conditions on the Bugzilla site: had to use trial and error. While entering this bug on this site right now webcompat.come/issues/new, I had to guess at where I was clicking to navigate the interface. In fact this interface is so TERRIBLE - I'm considering switching to Chrome. I hate Chrome. That's how much I hate this new Firefox. FYI I started on NCSA Mosaic in 1993, then Netscape, then when Firefox came out I've been using that ever since. I'm extremely disappointed that this upgrade makes it completely unusable for me. You should let your users choose vs force design changes.

Actual results:

Checkbox marks are invisible. Many Canva design elements are invisible. Firefox update happened automatically although I've gone in there several times and turned auto-update back off.

Expected results:

UI elements should show up as expected. Canva elements should show up as expected. Users should have the option of choosing drastic changes to their UI vs having forced on them.

(In reply to Sophia from comment #0)

Firefox 91.0 does not work with Canva: Firefox blocks out background images in designs. And, all the checkboxes on every page have white text so I have no idea whether they are clicked or not. Example: checking the box to accept terms/conditions on the Bugzilla site: had to use trial and error. While entering this bug on this site right now webcompat.come/issues/new, I had to guess at where I was clicking to navigate the interface.

This sounds pretty bad. Unfortunately I can't reproduce any of these issues with checkboxes and other UI being invisible or having white text etc. Can you provide a screenshot of what you're seeing (esp. of the checkboxes / white text) to help clarify what the problem is?

If you go into Firefox > Preferences, and look for "colors", is it possible you have custom colours configured that are set to override website choices?

The Bugbug bot thinks this bug should belong to the 'Core::Layout: Form Controls' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

You wrote: And, all the checkboxes on every page have white text so I have no idea whether they are clicked or not.

This can be caused by having set "browser.proton.enabled = false" on the about:config page to disable Proton.

See also the Firefox 91 release notes under New.
https://www.mozilla.org/en-US/firefox/91.0/releasenotes/
Firefox now automatically enables High Contrast Mode when "Increase Contrast" is checked on MacOS

(In reply to dickvl from comment #3)

You wrote: And, all the checkboxes on every page have white text so I have no idea whether they are clicked or not.

This can be caused by having set "browser.proton.enabled = false" on the about:config page to disable Proton.

dickvl: do you have more context on this issue? I wasn't able to reproduce this locally.

Firefox now automatically enables High Contrast Mode when "Increase Contrast" is checked on MacOS

Good find! This sounds very-likely like Sophia's issue, given that they're on Mac (based on first line of comment 0). I can confirm this behavior locally, too.

Sophia: assuming this theory is correct, you can avoid this issue by opting out of "override colors" mode, by doing the following:
(1) going to the Firefox Preferences page (type about:preferences into your URLbar or use Firefox app-menu at top-left to choose "preferences"
(2) Type "Colors" into the searchbox inside the preferences page (at the top right of the preferences page), and click the button labeled "Colors..."
(3) In the setting labeled Override the colors specified by the page with your selections above, choose Never. (The default is Only with High-Contrast Themes, which we apparently now includes the "Increase Contrast" setting on macOS.)

See also https://support.mozilla.org/en-US/kb/accessibility-features-firefox-make-firefox-and-we#w_overriding-page-colors which has similar steps.

(Alternately, you could of course just disable your macOS "Increase Contrast" setting, but presumably you want to keep that setting given that you've presumably opted into it.)

Checkboxes not working properly only happens on 91 with "browser.proton.enabled = false" and doesn't happen in 92 Beta and 93 Nightly.

Set release status flags based on info from the regressing bug 1713015

Given comment 5 should we close this as fixed in 92?

(In reply to Julien Cristau [:jcristau] from comment #7)

Given comment 5 should we close this as fixed in 92?

I would ideally like to hear from Sophia to confirm the issue is fixed either by changing the proton pref back, or using 92, or by changing the high contrast settings as outlined in comment #4. I'm not the triage owner and I defer to them, but in the components I triage we normally give the reporter 14 days to answer needinfo requests. :-)

Note that there are two different issues reported by Sophia, each with their own workaround.

The issue with the ckeckboxes should be fixed in 91 by setting browser.proton.enabled = true (or installing 92 Beta, but that moves you to the beta update channel with two updates per week).

The issue with the colors can likely be fixed by setting "Override the colors specified by the page with your selections above" to Never.

If this ends up being an HCM issue, let's close this as a dup to bug 1726606. I'll wait for Sophia to respond, though.