[GH-ISSUE #930] MonitorControl interferes with True Tone after waking from sleep #573

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opened 2026-05-05 06:16:42 -06:00 by gitea-mirror · 5 comments

gitea-mirror commented

2026-05-05 06:16:42 -06:00

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Originally created by @patrickrushton on GitHub (Feb 2, 2022).
Original GitHub issue: https://github.com/MonitorControl/MonitorControl/issues/930

Edit: After trying to reproduce this some more, I'm not convinced this is a MonitorControl issue, therefore I'm going to close it. Will reopen if I can figure out if it's really related to MonitorControl.

Before opening the issue, have you...?

Searched for existing issues

Looked through the wiki

Updated MonitorControl to the latest version (if applicable)

Describe the bug

When MonitorControl is not running, True Tone on my Macbook will adjust the warmth on both the integrated display and my external display. As long as MonitorControl is not running, the behaviour continues after waking from sleep.

With MonitorControl running, the behaviour is the same, but only until the Mac goes to sleep. After waking from sleep, the external monitor warmth is reset and no longer synced.

Steps to reproduce

Ensure True Tone is enabled in System Preferences

Start MonitorControl

Adjust ambient lighting to a warm colour.

Wait for both displays to adjust their tone and make a visual note or photo of the result.

Put the Mac to sleep

Wake from sleep

Colours on the external screen are now cool

To restore True Tone syncing to the external display, I have to disable and re-enable True Tone in Control Center or System Preferences.

Expected behavior

If the above steps are followed but instead quit MonitorControl in step 2, then in step 7 the warm tone of the external monitor is restored when waking from sleep.

Anything else?

Possibly related to https://github.com/MonitorControl/MonitorControl/issues/922
Unlike this issue, True Tone is not fixed by quitting and restarting MonitorControl. I have to toggle TrueTone off and on again to restore True Tone to the external display.

Environment Information (please complete the following information)
- macOS version: 11.2
- Mac model: MacBook Pro 2019
- MonitorControl version: 4.0.2
- Monitor(s): DELL U2713HM
- Apple Silicon/M1 (yes or no): no

Originally created by @patrickrushton on GitHub (Feb 2, 2022). Original GitHub issue: https://github.com/MonitorControl/MonitorControl/issues/930 Edit: After trying to reproduce this some more, I'm not convinced this is a MonitorControl issue, therefore I'm going to close it. Will reopen if I can figure out if it's really related to MonitorControl. > > ### Before opening the issue, have you...? > > - [X] Searched for existing issues > - [X] Looked through [the wiki](https://github.com/MonitorControl/MonitorControl/wiki) > - [X] Updated MonitorControl to the latest version (if applicable) > > ### Describe the bug > > When MonitorControl is not running, True Tone on my Macbook will adjust the warmth on both the integrated display _and_ my external display. As long as MonitorControl is not running, the behaviour continues after waking from sleep. > > With MonitorControl running, the behaviour is the same, but only until the Mac goes to sleep. After waking from sleep, the external monitor warmth is reset and no longer synced. > > ### Steps to reproduce > > 1. Ensure True Tone is enabled in System Preferences > 2. Start MonitorControl > 3. Adjust ambient lighting to a warm colour. > 4. Wait for both displays to adjust their tone and make a visual note or photo of the result. > 5. Put the Mac to sleep > 6. Wake from sleep > 7. Colours on the external screen are now cool > > To restore True Tone syncing to the external display, I have to disable and re-enable True Tone in Control Center or System Preferences. > > ### Expected behavior > > If the above steps are followed but instead quit MonitorControl in step 2, then in step 7 the warm tone of the external monitor is restored when waking from sleep. > > ### Anything else? > > Possibly related to https://github.com/MonitorControl/MonitorControl/issues/922 > Unlike this issue, True Tone is not fixed by quitting and restarting MonitorControl. I have to toggle TrueTone off and on again to restore True Tone to the external display. > > ### Environment Information (please complete the following information) > > ```markdown > - macOS version: 11.2 > - Mac model: MacBook Pro 2019 > - MonitorControl version: 4.0.2 > - Monitor(s): DELL U2713HM > - Apple Silicon/M1 (yes or no): no > ``` >

gitea-mirror closed this issue

2026-05-05 06:16:43 -06:00

gitea-mirror commented

2026-05-05 06:16:46 -06:00

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@dgmulf commented on GitHub (May 26, 2025):

This was closed as completed without any reference to the commit that supposedly fixed it, but it still remains a problem for me. In fact, MonitorControl seems to permanently break True Tone on any new user account, even after closing the app and restarting in Safe Mode. Does it persist changes to some OS-level user settings file?

@dgmulf commented on GitHub (May 26, 2025): This was closed as completed without any reference to the commit that supposedly fixed it, but it still remains a problem for me. In fact, MonitorControl seems to permanently break True Tone on any new user account, even after closing the app and restarting in Safe Mode. Does it persist changes to some OS-level user settings file?

gitea-mirror commented

2026-05-05 06:16:47 -06:00

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@waydabber commented on GitHub (May 27, 2025):

No, it does not alter any OS level config file. MonitorControl should not affect TrueTone in any way.

@waydabber commented on GitHub (May 27, 2025): No, it does not alter any OS level config file. MonitorControl should not affect TrueTone in any way.

gitea-mirror commented

2026-05-05 06:16:50 -06:00

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@dgmulf commented on GitHub (May 27, 2025):

Thank you for your reply. That's very odd. I did a carefully controlled experiment with a brand new user account on my system, and confirmed that True Tone stopped working for that account only after running MonitorControl, which persisted after a reboot. Does it run any other background process?

@dgmulf commented on GitHub (May 27, 2025): Thank you for your reply. That's very odd. I did a carefully controlled experiment with a brand new user account on my system, and confirmed that True Tone stopped working for that account only after running MonitorControl, which persisted after a reboot. Does it run any other background process?

gitea-mirror commented

2026-05-05 06:16:52 -06:00

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@waydabber commented on GitHub (May 28, 2025):

No, it does not run any background processes. Also, one can't interfere with True Tone easily programmatically.

@waydabber commented on GitHub (May 28, 2025): No, it does not run any background processes. Also, one can't interfere with True Tone easily programmatically.

gitea-mirror commented

2026-05-05 06:16:53 -06:00

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@dgmulf commented on GitHub (May 28, 2025):

I see. Sounds like a problem with the OS, then.

@dgmulf commented on GitHub (May 28, 2025): I see. Sounds like a problem with the OS, then.