1656637 - Extensions pages (options, sidebar, popup) are rendered with unreadable text color with the combination the "browser_style: true" and the "High Contrast" theme on Windows 10

Status: RESOLVED WONTFIX

(WebExtensions :: General, defect)

Description

[YUKI "Piro" Hiroshi]

Attachment: screenshot: what is expected and what is actual

This is an accessibility problem.

When I activate the "High Contrast" theme on Windows 10, all applications are shown with dark background with bright text. Firefox also respects the color scheme, and renders its UI and web contents with high contrast colors instead of colors specified in contents side. But contents provided by addons are excepted, and they become unreadable on the situation, as the attached screenshot.

When browser's style is applied to pages provided by an extension with "browser_style": true (it is activated by default, except it is intentionally canceled with "browser_style": false), a built-in style sheet extension.css is loaded as an agent sheet. It contains a fixed color declaration and it is applied even if we are in the high contrast mode. The text color cannot be overridden by the extension side (color declarations of author style sheets are ignored in the high contrast mode), so there is only one workaround: canceling to load the extensions.css with "browser_style": false.

Steps to reproduce

1. Start Windows 10.
2. Activate the high contrast theme. There is a guidance: https://support.microsoft.com/en-us/help/13862/windows-10-use-high-contrast-mode
3. Start Firefox.
4. Install any addon providing built-in pages with "browser_style": true. For example: https://addons.mozilla.org/firefox/addon/tabcenter-reborn/
5. Look at the sidebar provided by the addon.

Actual result

The sidebar contents is shown with dark background and dark text, so it is very unreadable.

Expected result

The sidebar contents is shown with bright text color defined by the high contrast theme of Windows 10 itself.

Environment

• Nightly 81.0a1 (build ID: 20200731094606)
• Firefox 79.0 (build ID: 20200720193547)
• Windows 10 Home 1909

Comment 1

[Shane Caraveo (:mixedpuppy)]

browser_style wont work with all themes and needs a lot of work to get there.

Comment 2

[Rob Wu [:robwu]]

Closing bug because support for browser_style feature is going to be removed (at least in MV3), see bug 1827910.