[GH-ISSUE #1036] Updating contrast turned screen purple #621

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opened 2026-05-05 06:23:14 -06:00 by gitea-mirror · 1 comment

gitea-mirror commented

2026-05-05 06:23:14 -06:00

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Originally created by @govindrai on GitHub (May 17, 2022).
Original GitHub issue: https://github.com/MonitorControl/MonitorControl/issues/1036

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

I adjusted contrast slider. after a couple of slides, the screen turned purple and is not reverting.

Steps to reproduce

Adjust contrast slider, many times (maybe 10-15 times)
Hope it doesn't turn purple :)

Expected behavior

It should not turn purple.

Anything else?

Quitting monitor control instantly returned it back to its normal state. unfortunately I copied mac version number on top my clipboard and lost the purple monitor image.

Environment Information (please complete the following information)

- macOS version: 12.3.1 (21E258)
- Mac model: MacBook Pro (16-inch, 2021)
- MonitorControl version: 4.0.2
- Monitor(s): HP E243
- Apple Silicon/M1 (yes or no): no

Originally created by @govindrai on GitHub (May 17, 2022). Original GitHub issue: https://github.com/MonitorControl/MonitorControl/issues/1036 ### 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 I adjusted contrast slider. after a couple of slides, the screen turned purple and is not reverting. ### Steps to reproduce 1. Adjust contrast slider, many times (maybe 10-15 times) 2. Hope it doesn't turn purple :) ### Expected behavior It should not turn purple. ### Anything else? ![image](https://user-images.githubusercontent.com/13859249/168737593-cd1e91ed-7793-4928-9eb2-f13a727a335b.png) Quitting monitor control instantly returned it back to its normal state. unfortunately I copied mac version number on top my clipboard and lost the purple monitor image. ### Environment Information (please complete the following information) ```markdown - macOS version: 12.3.1 (21E258) - Mac model: MacBook Pro (16-inch, 2021) - MonitorControl version: 4.0.2 - Monitor(s): HP E243 - Apple Silicon/M1 (yes or no): no ```

gitea-mirror

2026-05-05 06:23:14 -06:00

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gitea-mirror commented

2026-05-05 06:23:20 -06:00

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@waydabber commented on GitHub (May 18, 2022):

The contrast slider sends an appropriate DDC command to the display - but contrast is not universally supported (or sometimes not properly supported) by some displays - so this is highly display firmware specific. If the display turned purple, the firmware might have messed up the color channels. If you find the OSD adjustment for this, you can fix it or you might have to reset the display.

@waydabber commented on GitHub (May 18, 2022): The contrast slider sends an appropriate DDC command to the display - but contrast is not universally supported (or sometimes not properly supported) by some displays - so this is highly display firmware specific. If the display turned purple, the firmware might have messed up the color channels. If you find the OSD adjustment for this, you can fix it or you might have to reset the display.