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How to fix the Night light mode not work after toggle Second screen only mode?

Vu Ha Minh Trang 0 Reputation points
2026-04-24T02:49:54.4166667+00:00

I regularly work with an external monitor and prefer using Night Light mode on both my laptop and the external display to reduce eye strain.

However, I discovered that after connecting an external monitor and changing to Duplicate mode, if I turn off Night Light, then switch to Second Screen Only mode, the Night Light strength cannot be modified or turned off on the external monitor.

Then, if I switch back to Duplicate mode, Night Light also becomes unresponsive on my laptop as well as the external monitor, and this problem continues until I restart the laptop.

User's image

As you can see in the image, even though the Night Light strength is set to 100 in the settings, the screen color barely changes.

So is there a way to avoid or resolve this issue?

Windows for home | Windows 11 | Display and graphics

2 answers

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  1. nobuko c 124.1K Reputation points Independent Advisor
    2026-04-24T06:31:22.9433333+00:00

    Hello,

    This behavior is commonly seen on laptops when switching between display modes (Duplicate → Second screen only → back to Duplicate). Laptops use two different display pipelines (the internal panel and the external monitor), and when

    Windows reconfigures these pipelines, the color‑temperature processing used by Night light sometimes fails to re‑initialize correctly.

    When this happens, the Night light slider still moves, but the actual color temperature does not change on either screen until the system is restarted.

    Some manufacturers also document similar behavior on certain laptop models, describing it as a limitation in how the color‑temperature pipeline is handled when external displays are enabled or disabled. Although their explanations are

    hardware‑specific, the same behavior has been reported for years across Intel, AMD, and ARM laptops, which suggests that this is a long‑standing limitation in the current Night light implementation rather than a device‑specific defect.

    There is no permanent fix at the moment, but these workarounds help avoid the issue:

    1. Turn Night light off before switching to “Second screen only”.
    2. After switching display modes, toggle Night light off → on again.
    3. If Night light becomes stuck, switching temporarily to “PC screen only” sometimes restores it without rebooting.
    4. Avoid changing display modes while Night light is active.

    This is not caused by your hardware or GPU driver. It is a known behavior of how Windows handles Night light during display‑pipeline changes on laptops.

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  2. AI answer

    2026-04-24T02:50:16.26+00:00

    This behavior is consistent with a display/driver issue rather than a configurable Night light setting.

    From the available information, the only supported ways to address Night light problems are:

    1. Verify and update the display/graphics drivers
      • If the Night light toggle or its effect becomes unresponsive after switching display modes, update the display driver.
      • Go to Device Manager → Display adapters and update the driver, or install the latest graphics driver from the device or GPU manufacturer.
      • The Night light documentation explicitly notes that if the Night light toggle is grayed out or not working correctly, updating the display driver is required.
    2. Adjust Night light settings only after the driver is stable
      • Open Start → Settings → System → Display → Night light.
      • Use the Strength slider to adjust the intensity of the blue light reduction.
      • Optionally, enable Schedule night light so it turns on/off automatically instead of toggling it repeatedly while switching between Duplicate and Second screen only modes.
    3. If HDR is enabled on an HDR-capable display
      • On HDR-capable devices, colors can appear off or oversaturated when Night light is on. If HDR is enabled, reduce the Strength slider or temporarily turn Night light off from Settings → System → Display → Night light.

    If the issue persists even with up‑to‑date display drivers, the supported workaround is to restart the device when Night light becomes unresponsive after changing projection modes.

    References:

    AI-generated content may be incorrect. Read our transparency notes for more information.

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