[Windows 11] "Sync with OS" theme option results in inverted themes when toggling with PowerToys

[chenx-dust]

Pre-submit Checks

• I have searched Warp bugs and there are no duplicates
• I have searched Warp known issues page and my issue is not there
• I have an issue with AI and have included the debugging ID (Optional, but helps expedite the AI quality fix). Debugging ID instructions
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Describe the bug

When using the "Sync with OS" theme setting on Windows 11, dynamically switching between light and dark themes using Microsoft PowerToys causes an inverted theme configuration (i.e., the app switches to the dark theme when the OS is in light mode, and vice versa).

Investigation

This issue stems from how the underlying winit library reads the system theme. Reading the theme via uxtheme.dll introduces a delay/race condition during rapid or automated toggles, which leads to out-of-sync states. The system theme should instead be read directly from the Windows Registry to ensure immediate and accurate updates.

Pull requests

I have submitted a fix to the Warp-scoped winit fork, and a similar upstream fix is also under discussion:

• Warp winit PR (Fix): fix(windows): use registry value to detect dark mode winit#16
• Upstream winit PR (Reference): fix(windows): use registry value to detect dark mode rust-windowing/winit#4453

To reproduce

1. Open Warp.
2. Use "Light Switch" in PowerToys to toggle OS theme.

Expected behavior

Theme of the application should sync with OS.

Screenshots, videos, and logs

20260601-1240-28.8991285.mp4

Operating system (OS)

Windows

Operating system and version

Windows 11 25H2 (Build 26200.8524, Simplified Chinese)

Shell Version

No response

Current Warp version

v0.2026.05.27.15.44.stable_01

Regression

No, this bug or issue has existed throughout my experience using Warp

Recent working Warp date

No response

Additional context

No response

Does this block you from using Warp daily?

No

Is this an issue only in Warp?

Yes, I confirmed that this only happens in Warp, not other terminals.

Warp Internal (ignore): linear-label:b9d78064-c89e-4973-b153-5178a31ee54e

None

[oz-for-oss]

@chenx-dust

Here's what I found while triaging this issue:

Thanks for the detailed repro, video, and linked fixes. This looks actionable as a Windows-specific Sync with OS bug; the linked winit fix targets the same native dark-mode path that still differs from Warp's registry-based app theme read.

Maintainer details

I concluded that windows Sync with OS theme switching can invert light/dark themes when PowerToys Light Switch toggles the OS theme, likely due to Warp's pinned winit fork still using the Windows uxtheme dark-mode API in its native dark-mode path..

Triage

This is a Windows-specific bug in Sync with OS theme switching: using PowerToys Light Switch to toggle Windows 11 light/dark mode can leave Warp inverted, with the dark theme active when the OS is light and vice versa.

Evidence

• The report includes Windows 11 25H2 build details, Warp v0.2026.05.27.15.44.stable_01, clear reproduction steps, and a video attachment.
• Warp's theme settings derive the active theme from the platform SystemTheme when Sync with OS is enabled.
• The current Warp-side Windows SystemTheme read uses the AppsUseLightTheme registry value, but Warp pins warpdotdev/winit to a revision whose Windows native dark-mode path still uses the undocumented uxtheme.dll ShouldAppsUseDarkMode API. The linked warpdotdev/winit#16 changes that winit path to registry reads, which matches the reporter's hypothesis.

Likely root cause

The pinned winit fork can apply or report Windows dark mode from stale/incorrect uxtheme state during automated theme toggles. That makes the report actionable as a dependency/windowing issue rather than a simple settings mapping bug, though I am keeping confidence at medium because I could not reproduce the Windows-only behavior in this environment.

Duplicate check

I scanned all open non-PR issues and recently closed issues. The closest matches (#11940, #8748, #723, and #1509) are adjacent Windows/theme/PowerToys or Sync with OS issues, but they do not describe the same inverted Sync with OS behavior triggered by PowerToys Light Switch.

This is my automated analysis and may be incorrect. A maintainer will verify the details.

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[kevinchevalier]

@acarl005 Can you take a look?