Since updating to macOS 10.12 Sierra, there has been an increase in artifacts in regions of images where color transitions from dark to light.

Consider the following image: Demo image

While processing the image in Adobe Photoshop 14.0.0, there was no evidence of artifacts in the darker color transitions. However, upon opening the image in Preview, this was the result:

Demo image with weird color transitions

Here is a closer inspection:

Demo image with weird color transitions close-up

Around the edges where the color transitions from dark to light, there is a strange pattern consistent with temporal dithering. I have confirmed that it does not only occur in this image, but in other images where there are transitions between dark and light colors.

Strangely, this only occurs in Preview, QuickLook, iMessage, Chrome and almost any other application, but not in Adobe Photoshop. The patterns/artifacts can be captured by a screenshot.

Does anyone know what causes this issue, if it is of concern, if it can be avoided/disabled or any other information about this issue? Help is much appreciated.

  • What color profile are you editing the image in?
    – Agos
    Commented Oct 11, 2016 at 7:53
  • My computer screen is set to a color-calibrated display, and the image was processed on an external monitor on Adobe RGB. Commented Oct 11, 2016 at 7:59
  • How are you exporting the file? Is your monitor properly calibrated?
    – Agos
    Commented Oct 11, 2016 at 10:12
  • The monitor is properly calibrated. The image is exported in Adobe RGB, and works fine on the Adobe RGB display - I figured that the Adobe RGB color space might be slightly wider than the sRGB one, so I decided to try changing my MacBook's monitor to Adobe RGB. Turns out, that was the problem. I'd be happy to accept your answer for pointing me in the right direction (if you'd like to post one). Commented Oct 11, 2016 at 10:49

1 Answer 1


Upon further investigation on color profiles after Agos's comment pointed me in the right direction, it turned out that using the incorrect color profile was responsible for the dither-like regions.

For others who have a similar issue, navigate to System Preferences > Displays > Color and select the profile that the image was exported in.

I would assume that the dithering-like region was due to the colors in that region being out of the color space of sRGB, and as a result the computer attempts to compensate.

  • Watch out for Auto Brightness on macOS and El Capitan adjusting the gamma. mackungfu.org/… Commented Oct 12, 2016 at 11:39

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