User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:73.0) Gecko/20100101 Firefox/73.0

Steps to reproduce:

I am logging to Google and create or open Google Spreadsheet when High Contrast Mode in On in Win10. Also the background color in FF is set to black and text to white and checkbox marked with Use system colors.

Actual results:

Google SpreadSheet page is loading - the sheet cells are black and after loaded it becomes white. Written text is also white. I have tried to find any solution inside Google Spreadsheets - none found. I have also tested in FireFox Nightly - no impact. Also in about.config display.permit_backplate - true or false - no impact.

Expected results:

It should be the same as during loading. Cells in Spreadsheet should have black background. It was like this a years ago, than something was changed (in Google or FF - I don't know).

They're using a <canvas> to render everything once it loads, so it's not something we have much control into unfortunately... I think this would be better reported as a Google Sheets bug.

Mike, do we have contacts at google docs? They could in theory use the default background-color and colors of the page to respect user preferences.

Yep, I've sent an email to them on our "gsuite" mailing list. I'm not sure if they'll consider it as a feature request or a bug, but it's in their hands now.

We appreciate your report. Based on what you described and following the steps to reproduce and other scenarios, the issue can be reproduced on other browsers and it is not a Compatibility issue. Following the steps to reproduce, and with the altered settings, Chrome and Firefox exhibit the same behavior

This is the result using Firefox Nightly:
https://prnt.sc/EGze-O2NETEn
https://prnt.sc/guC5SrB_t4xB
https://prnt.sc/gIagUzEFOoAP
https://prnt.sc/LNFQhnGSnr2m

And this is the result using Chrome:
https://prnt.sc/-0RT1NpEu3sA
https://prnt.sc/K_Lc9otgGF9Q
https://prnt.sc/caYXC_Uj4eYS
https://prnt.sc/KtFb1zPChMqp

For this project, we try to focus our effort on layouts, features, or content that works as expected in one browser but not in another.

Tested with:

Browser / Version: Firefox Release 100.0.2 (64-bit)/ Firefox Nightly 102.0a1 (2022-05-24) (64-bit) / Chrome Version Version 102.0.4004.63 (Official Build) (64-bit)
Operating System: Windows 10 PRO x64

Closing this as Non-compat