Sidebar/toolbar stays dark in light mode on Wayland (prefer-light ignored, only chrome affected)

[MeinardEdrei]

Preliminary Checks

• I have read and understood the important section above.
• I have searched existing issues and avoided creating duplicates.
• I am not filing an enhancement request.
• I have checked that this issue cannot be reproduced on Mozilla Firefox.
• I have checked that this issue can be reproduced once I removed all my Mods and Custom CSS.

What happened?

When the system color scheme is set to prefer-light, the sidebar and toolbar chrome remain dark while the page content area correctly switches to light. The result is a mixed dark/light UI. Dark mode works correctly — this only affects light mode.

Expected behavior

Sidebar and toolbar should follow the system light color scheme, matching the content area.

Actual behavior

Sidebar/toolbar stays dark regardless of system color scheme being set to prefer-light. Content area renders light correctly. Switching to prefer-dark makes the full UI dark correctly — only light mode is broken.

Steps to reproduce

1. On a Wayland session, set system color scheme to light: dconf write /org/gnome/desktop/interface/color-scheme '"prefer-light"'
2. Launch or focus Zen Browser
3. Observe sidebar/toolbar is dark while page content area is light

Screenshots and videos

Version

1.19.11b

What platform are you seeing the problem on?

Linux (Wayland)

What component is this issue related to?

Mods / Themes

Relevant log output if applicable

# XDG portal correctly returns prefer-light:
gdbus call --session --dest org.freedesktop.portal.Desktop \
  --object-path /org/freedesktop/portal/desktop \
  --method org.freedesktop.portal.Settings.Read \
  org.freedesktop.appearance color-scheme
# Returns: (<<uint32 2>>,)  ← prefer-light confirmed

# about:config state:
widget.use-xdg-desktop-portal.settings = 1
extensions.activeThemeID = default-theme@mozilla.org
zen.theme.use-system-colors = true
zen.theme.dark-mode-bias = 0.3
browser.theme.toolbar-theme = 2 (auto-overwritten by Zen on startup, cannot be persistently changed)

# No userChrome.css, userContent.css, or active WebExtension themes present
# Issue persists even when forcing prefer-light directly via dconf, bypassing compositor entirely

[sporocyst]

Have you choose the star icon in theme editing panel?

[MeinardEdrei]

yes, i checked it and tried the light mode option too

[mr-cheffy]

You did enable zen.theme.use-system-colors though? Thats the entire point of the pref