1990082 - [Windows 10][A11y] The Cancel, Save, Edit comment and Remove comment buttons are displayed as blank in High Contrast #1 and #2

Status: VERIFIED FIXED

(Firefox :: PDF Viewer, defect)

Description

[Daniel Bodea [:danibodea]]

Attachment: High contrast button text missing.png

Note

• The Cancel, Save, Edit comment and Remove comment buttons are are not displaying the text/icons in High Contrast #1 and High Contrast #2 whe4n the buttons are enabled.

Found in

• Nightly v145.0a1

Affected versions

• Nightly v145.0a1

Tested platforms

• Affected platforms: Windows 10
• Unaffected platforms: Windows 11, MacOS, Ubuntu

Steps to reproduce

1. Set High Contrast #1 and High Contrast #2 theme.
2. Load a PDF (https://ontheline.trincoll.edu/images/bookdown/sample-local-pdf.pdf)
3. Select some text and click the Comment button.
4. Insert some text.

Expected result

• The Cancel and Save buttons are correctly displayed.

Actual result

• The Cancel and Save buttons are missing their text.

Regression range

• Not a regression.

Additional notes

• The same issue occurs when clicking the Comment icon to read an existing comment; The Edit comment and Remove comment icons are missing from the buttons.

Comment 1

[Anna Yeddi [:ayeddi] (Leave starting on July 3, 2026)]

Missing active UI (missing controls) in the High Contrast Mode (HCM) is an access-S2 issue that makes this part of the UI inaccessible for users that rely on high contrast themes (those with low vision, users with cognitive disabilities, users with dyslexia, with colorblindness, and others). We need to ensure the appropriate color pairs are used for forced-colors media query (HCM on Win): ButtonFace with ButtonText for the border/label text and for the control background.

I am wondering why only Win10 is affected but Win11 is not? Possibly, the system colors are not used and the Win11-specific colors are hard-coded, thus they are appearing more readable on Win11 because the system colors expected there are similar to the hard-coded values while both Windows 10 themes are using other colors? From the screenshot, this seem to be an issue, because the Win 10 themes #1 or #2 do not have any yellow color.

Adding a Figma reference for color combinations for different Win10 and Win11 themes (SSO required), and you could check the computed colors for the expected system colors on your specific HCM on any Windows machine using the Web Palette Checker

Comment 2

[BMO Github Automation]

Attachment: [mozilla/pdf.js] [Editor] Avoid to use similar colors for background and foreground colors in HCM (bug 1990082) (#20298)

Comment 3

[Daniel Bodea [:danibodea]]

This fix is verified in Nightly v145.0a1 on Windows 10 x64 with both Hich Contrast #1 and High Contrast #2 Themes. The previously affected buttons are now correctly displayed. Cancel, Add/Update, Edit comment and Remove comment buttons are no longer displayed as blank.