Night Light enabled only on one external monitor - Redshift alternative works

Activated Night Light Applet from sunset to sunrise.

It finally works after uninstalling Brightness Control Applet, but only on the left screen of the dual monitor setup.

Anybody seen the same issue?


Seems to be a GNOME issue -

Reading through on the linked issue

it mentions killall gsd-color although the bug-report is closed saying that its fixed in mutter 3.28. So looks like there are more issues here with your setup - other people seem to be having the same issue on that report after the fix was released … so looks like it is not fully fixed.

thx for your help.

The links show exactly my problem.

Did a killall gsd-color and now Night Shift doesn’t work on both monitors.
Tried changing color profile settings, turning off and on monitors, but still no Night Shift function.

I guess we simply have to wait for a fix.

Night light doesn’t work, tried other tweaks today.

Instead i tried Redshift, but it gets a geoclue2 error, even with geolocation enabled in settings -> privacy.

It works with a redshift-config file:

Install Redshift:
sudo apt install redshift-gtk

Create redshift.conf to avoid geoclue2 error:
sudo gedit ~/.config/redshift.conf

( Redshift ver. 1.12+ looks for the configuration file in ~/.config/redshift/redshift.conf (or ${XDG_CONFIG_HOME}/redshift/redshift.conf ) if $XDG_CONFIG_HOME is set. The old location at ~/.config/redshift.conf is deprecated but still searched as a fall back.)

Paste this text into the redshift.conf file and customize your geolocation (google your city for lat & long):

; Global settings for redshift
; Set the day and night screen temperatures

; Enable/Disable a smooth transition between day and night
; 0 will cause a direct change from day to night screen temperature.
; 1 will gradually increase or decrease the screen temperature.

; Set the screen brightness. Default is 1.0.
; It is also possible to use different settings for day and night
; since version 1.8.
; Set the screen gamma (for all colors, or each color channel
; individually)
; This can also be set individually for day and night since
; version 1.10.

; Set the location-provider: ‘geoclue’, ‘geoclue2’, ‘manual’
; type ‘redshift -l list’ to see possible values.
; The location provider settings are in a different section.

; Set the adjustment-method: ‘randr’, ‘vidmode’
; type ‘redshift -m list’ to see all possible values.
; ‘randr’ is the preferred method, ‘vidmode’ is an older API.
; but works in some cases when ‘randr’ does not.
; The adjustment method settings are in a different section.

; Configuration of the location-provider:
; type ‘redshift -l PROVIDER:help’ to see the settings.
; ex: ‘redshift -l manual:help’
; Keep in mind that longitudes west of Greenwich (e.g. the Americas)
; are negative numbers.

; Configuration of the adjustment-method
; type ‘redshift -m METHOD:help’ to see the settings.
; ex: ‘redshift -m randr:help’
; In this example, randr is configured to adjust screen 1.
; Note that the numbering starts from 0, so this is actually the
; second screen. If this option is not specified, Redshift will try
; to adjust all screens.

Log off and log in. Works on all screens! :sunglasses:
You may uncomment brightness-day, brightness-night to lower brightness too, but it starts to pulse brightness on my screens, so i left it commented (disabled).

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