Fixing Night Shift incompatibility with external monitors
If you use an external monitor for your Mac of any shape or size and recently updated to macOS Sierra 10.12.4, chances are you've had some trouble with Night Shift.
Common issues include:
- the inability to configure Night Shift from your external monitor
- Night Shift being impossible to disable (as a result of the former)
- a substantial loss of colour quality (as a result of both of the former happening at once on some connection or screen types, most commonly DVI-D to VGA, DisplayPort, and LCD screens of all kinds.)
How do you get past these issues? Is there a way to enable access to the Night Shift pane on any display?
Unplug the cable and insert it again.
It works for me.
Update for Catalina (macOS 10.15): For secondary monitors, you may have to unplug primary monitor, so that the secondary monitor is the primary monitor. (Doing this once should be enough)
by @Michael_Scharf
For me the following worked:
- disable night shift
- disconnect external display
- reconnect external display
- enable night shift
After two days of searching, I've found a solution that allows users to get past the Night Shift incompatibility issues with external monitors. This solution helps to enable access to Night Shift on any display.
- Connect your external monitor, disable your internal monitor, and make sure your external monitor is set as the default.
- Download required files. You will need two programs (and a third optional) to proceed. The first is FixEDID, which can be found here: FixEDID, the second is DarwinDumper and can be found here: DarwinDumper, and the final (optional) one is KextWizard, found here: KextWizard
- Open FixEDID, wait for the fields to auto-load, and minimize FixEDID, do not close it.
- Open DarwinDumper, click Deselect All, check the EDID box, and click Run. You will be prompted for your password, and the dump directory will auto-open when it is done. Close DarwinDumper, and copy EDID.bin to your desktop.
- Unminimize FixEDID, click Open EDID Binary File, select your EDID.bin. Now in the drop down menu under that button choose the internal monitor for your model of Mac (this will usually be the first option), and click the Make button. You should have a few new files now, but you can ignore all of them except DisplayMergeNub.kext, which you will need.
- (Kext Wizard Version) Open Kext Wizard, click the Installation tab, click Browse, choose DisplayMergeNub.kext, and click Install. You will be asked for your password. Once it has finished reboot your Mac.
- (Manual Installation) Open Terminal.app and run the following command
sudo mv $(whoami)/Desktop/DisplayMergeNub.kext /System/Library/Extensions/ && sudo reboot. You will be asked for your password, and your Mac will automatically reboot as soon as the operation finishes. - Upon rebooting you can go to Apple > About This Mac and under the Displays tab you will find your Mac now considers your external monitor to be your internal monitor, as a result Night Shift should not be auto enabled anymore, and you can now access the Night Shift preference pane from Settings.
A Quick Note
For those who want to reverse this process so that your external monitor is no longer considered a built-in display by your Mac, you can simply run the command sudo rm /System/Library/Extensions/DisplayMergeNub.kext && sudo reboot.
As with the previous command this will ask for your password, and automatically reboot your Mac after the process is finished.
UPDATE: 01/04/2019 As of later versions of macOS 10.13 and all versions of 10.14 external displays are being recognized natively when they are the only connected display. Thus this information should be considered deprecated except to those using a secondary external display, or those running macOS versions 10.12.4-10.13.4
After trying above solutions without success, I found the "true tone" setting in "display settings" of "system preferences", unchecked it, and external monitor became normal white again. Just in case it may help someone. I have an LG 4k with a USB-C cable.
Another option is to download Flux. It is an alternative to NightShift, and reliably works on both internal and external monitors. It acts as a replacement to NightShift, so should not be run together.