I have a BenQ BL3201 display, connected via HDMI (and a USB-C dongle) to my 2019 15" MacBook Pro. Light grey areas are completely washed out, and appear white. I've attached some photos to demonstrate.

Built-in Display:

Built-In Display

External Display:

External Display

I've adjusted the brightness, contrast, gamma, and every other setting on the monitor, but none of it resolves this problem. The monitor even has a special 'M-BOOK' mode for MacBooks that doesn't improve things at all. I've gone through every available display profile, and the only one that helps with this issue is 'ACES CG Linear' (but it looks worse in other ways, colours are very dark and muted).

The monitor was previously attached to to a Desktop Linux box, and it didn't show the same issue there.

Is there any setting or tweak that I can use to resolve this issue?

5 Answers 5


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I had this exact problem of the external monitor having washed out colors and, for me, the solution was to uncheck "High Dynamic Range"

  • +1 for this solution... expert mode for color calibration made the issue worse, but disabling HDR did it instantly! Aug 5, 2021 at 17:57
  • 1
    Still relevant in 2022. After upgrading to Monterey I began having this issue. Disabling that checkbox fixed it instantly. Apr 28, 2022 at 14:50
  • disable HDR fix it for me thanks for the hint Jan 10, 2023 at 6:07
  • 1
    In 2023, worked for me as well.
    – noname
    Apr 10, 2023 at 5:30

It does look like a calibration issue.

The only way to properly calibrate is with a hardware colorimeter [anywhere from $£€ 70 to $£€ 250 & upwards] but you can try to get the worst of it fixed yourself…

System Prefs > Displays > Colour
You get one of these per display & interacting with each will affect that display only.
To the right is a Calibrate… button, which can give a very general set of tweaks - however, if you hold Opt before clicking it, it will open out some more complex adjustments. In the first window that pops up, add 'Expert Mode' to get as much detail as possible without a hardware meter.


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  • Thanks! That helped, I was able to get the light greys looking right. Now I get some banding in photographs and gradients, though. I'm going to keep trying different adjustments, I'll accept this answer when I get everything working.
    – fiirhok
    Jun 24, 2020 at 19:35
  • Apple really loves to hide things with some magic shortcut key
    – somebody4
    Dec 4, 2021 at 9:11
  • 1
    Note that in Monterey this option appears in Settings > Displays > Display Settings... > Color Profile > Customize > + to add (while holding Alt AKA Option for "Expert Mode") The High Dynamic Range setting from the preferred solution didn't show up for me, so the advanced calibration worked perfectly for me :)
    – Noob
    Jul 7, 2022 at 11:21

I finally fixed this by following the instructions at this blog post:

Fixing the External Monitor Color Problem with My 2018 MacBook Pro

Read the blog post, it's good! But just in case it becomes unavailable, here's a short summary:

The external monitor is using the YPbPr colour format over HDMI. Something about the MacBook Pro YPbPr output is not compatible with the monitor. It's possible to create override settings to force the HDMI connection to use RGB instead, using a script at https://gist.github.com/adaugherity/7435890.

Here are the instructions from the above post:

  1. Connect the problematic display.
  2. Download and run this script (./patch-edid.rb). Take a look at the generated file and remember its path.
  3. Reboot into recovery mode (⌘-R at boot).
  4. Mount your main disk (enter Disk Utility, select the gray Macintosh HD, click Mount, provide your password, close Disk Utility).
  5. Open up a terminal (Utilities ->Terminal), backup the overrides directory, copy in your new override file, and reboot:
cd /Volumes/Macintosh\ HD/System/Library/Displays/Contents/Resources 
cp -R Overrides Overrides.bak 
cp -R <path to directory generated in step 1> Overrides/ 

I had the same problem and using Display Port resolved it. It seems when using HDMI with a Mac it thinks the monitor is a TV and the pixels are slightly out of alignment causing the banding and a red/green hue on text.


Heres what helped me solve the issue.

  1. System Preferences->Displays

    In the display settings of the external monitor you might see 2-3 options under "Scaled". Its very likely that these options arent a fit for your monitor.

  2. In the display settings of the external monitor, click on "default for display" -> press the "option key" and now click on "Scaled" radion button. You will now see a lot more resolution options (insane)... Select the resolution that matches your display. If unsure, try them all out, one of them will standout in terms of clarity.

  • can confirm this solution was the one for me too. changing from "scaled" to "default for display" solved the washed out colours problem
    – fcagnola
    Apr 16, 2022 at 16:41

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