f.lux reporting 1900K, but screen is still at 6500K.

  • I'm having an issue where it isn't working at all, my OS is Windows 10 Enterprise Insider Preview (Build 18305). I also reinstalled it and it didn't work in fixing it.

  • I upgraded to Build 18305.1003, and even made sure that the full color range was turned on (I restarted). Same issue.

  • Microsoft Night Light might be enabled and overriding f.lux.

  • Windows Night Light is not enabled.

  • Damn. Hmm. I think (but I'm not certain) I had this happen to me on my computer (and I have Windows 7). If I can recall what caused it and how I fixed it, I'll post again. That's the best I can do at the moment.

  • Same issue here. 10 Pro IP 18305. f.lux launches, stays in the tray, shows notifications, but won't change colors. Windows Night Light isn't working either.

  • f.lux team

    Do you have any HDR options on? Or an HDR-capable monitor?

  • f.lux team

    Also can you post f.lux options > Driver info?

    One report of this so far included a recent NVIDIA update, so I'm trying to tell whether this is 18305 or NVIDIA.

  • f.lux team

    "Night Light functionality has been impacted by a new bug in this build. Root cause is underway, and we expect to have this fixed in an upcoming build."


  • I have the same problem after the update W10 Pro & W10 Home Insider preview. Windows Night Light is disabled

  • Same Problem. Windows 10 Enterprise Insider preview 18305. Was working fine in 18298. I'm on Intel HD 510 btw, so probably not an issue with NVIDIA

  • @herf
    Sorry for a late response! here's the info. Currently it seems to be semi-working, as the color temperature is changing as expected, although hotkeys, disable/enable, exiting f.lux or dimming is not working.

    Also I posted this in Reddit around the time of my original comment and someone said there "Night Light and F.lux not working in 18305 is a known issue" without specifying known to whom.

    f.lux 4.86
    None of displays is HDR capable
    Night Light is turned off
    "V223HQL (Digital)" is 3 FHD panel spanned using NVIDIA Surround

    Intel Corporation Intel(R) HD Graphics 3000 (20160519)
    NVIDIA NVIDIA GeForce GTX 1070 (20181129)

    V223HQL (Digital), 1440 x 290mm, built 2013
    R=0.639648 0.330078
    G=0.299805 0.599609
    B=0.150391 0.059570
    W=0.313477 0.329102

    sRGB gamut: 100%, AdobeRGB gamut: 64%

    Generic PnP Monitor, 337 x 270mm, built 2005
    R=0.634766 0.336914
    G=0.287109 0.613281
    B=0.143555 0.085938
    W=0.312500 0.329102

    sRGB gamut: 93%, AdobeRGB gamut: 65%

    NEC LCD93VXM, 376 x 301mm, built 2009
    R=0.640625 0.336914
    G=0.303711 0.620117
    B=0.140625 0.073242
    W=0.313477 0.329102

    sRGB gamut: 93%, AdobeRGB gamut: 66%

    Windows Build: 18309

  • f.lux team

    temporary fix here:

    We are waiting on MSFT for the real fix.