I just got a Samsung Galaxy S9 last week and since day 1 it has been applying a blue light filter even though I turned blue light filter off in the settings (Blue Light Filter turned off and also schedule turned off under Settings/Display/Blue light filter).

The blue light filter's behavior is strange. The filter turns on around 6:56 every evening and turns off around 5:56 in the morning. Sometimes when I unlock my phone the filter isn't applied and a split second later I see it get applied. Even less often I see it applied in blocks quickly filling the screen. If I turn blue light filtering on in Display settings, the affect is additive.

When I got the phone all of the applications from my previous phone, a OnePlus 3, were installed, so I supposed it could have been one of those. I went into application permissions and turned off overlay permission (Settings/Apps/Special Access/Apps that can appear on top) to everything I thought might be affecting the screen color.

What else can I look into? Is there a way to check every process that's running to see what is changing the screen color?

  • Do you have Auto Brightness set ON? If you have recently turned it OFF, did you flush the usage data?
    – wbogacz
    Commented Jun 7, 2018 at 14:05
  • @wbogacz Auto Brightness is on. I've only briefly turned it off while trying to figure this out. Where do I flush usage data?
    – Matt Casto
    Commented Jun 8, 2018 at 13:52
  • Tap the Auto Brightness LABEL to bring up the submenu where you can flush usage data (At least this is functionality on the Galaxy S8). If the option is disabled, temporarily turn Auto Brightness ON, flush, then OFF again.
    – wbogacz
    Commented Jun 8, 2018 at 15:09
  • Flushing usage data did not work.
    – Matt Casto
    Commented Jun 9, 2018 at 15:46
  • 1
    Just making sure you saw this thread about using adb to disable a buggy night mode: forum.xda-developers.com/galaxy-s9-plus/help/… or use Nova Launcher reddit.com/r/GalaxyS9/comments/85blz5/… Commented Jun 12, 2018 at 21:07

2 Answers 2


So I did a bit of digging and found two related threads describing your problem:

User Friendly Solution

As you've described you had transferred over your settings from a different device and the 'Night Light' settings were hidden by the Samsung software.

The most user friendly way is from Reddit:

PSA: Night Light and Blue Light Filter Overlap

where the solution is use Nova Launcher and to create a Night Light shortcut from Nova Launcher:

Easy fix is through Nova Launcher / Activities. Press somewhere on the home screen so you can select widgets. From there select Activities>Settings>Night Light. Open Night Light from your home screen and turn it off - and the scheduling, too, of course... Unless you'd rather use Night Light.

Reddit author made a video for visual aid: https://youtu.be/J9J1B2Q8Eu4

Alternate ADB solution

In my research I also found a different way, and while it didn't help you perhaps it may help someone else:

Weird Night Mode type issue

The XDA one lists adb commands to try:

Using adb to list out device settings

adb shell 'settings list secure

and then attempting to clear the appropriate ones:

adb shell 'settings put secure night_display_activated 0'

adb shell 'settings put secure night_display_auto_mode 0'

I landed on this question + answer for a similar problem on a Motorola Moto G6 instead of a Samsung: the screen takes a slightly red-ish tint in the evening until the morning.

For the Motorola phone, there is an independent set of screen settings which includes a night mode (it's a blue screen filter with a schedule, not a black and white mode).

To access it, open the "Moto" application, head to "Features" ("Fonctionnalités" en français), expand the "Moto Screen" settings ("Écran Moto" en français), then enable, disable or configure the "Night screen" (Écran nuit" en français).

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