darkreader: [Broken Website] Comment text areas on canvas.*.edu sites don't invert properly

Prerequisites

• I searched for any existing report about this website issue to avoid opening a duplicate.
• I can reproduce this website issue in a new, unmodified web browser profile with Dark Reader installed as the only extension.

Website Issue Description

When using Canvas sites for a given institution, it looks like some of the textarea elements aren’t inverting properly. The font is, but the actual background of the textbox does not.

Website Address

canvas.*.edu (if you have an accessible instance of Canvas)

Steps To Reproduce

1. Log into an instance of Instructure’s Canvas platform
2. Navigate to a grade section, where you can enter a grade and leave comments.
3. Observe that the textarea elements’ backgrounds are white with a very light gray font.

Screenshots

Operating System

Windows 10

Web Browser name and version

Firefox 122.0.1

Dark Reader version

Version 5 Preview (4.9.77)

Additional Context

I can provide CSS info if need be, as this might be a tricky place to get to.