I recently moved from a 2017 macbook pro to a 2018 macbook pro with a configuration like this:

# Works perfectly    
MBP 2017 -> USB C -> Displayport -> Dell Ultrasharp U2415

# Red / blue font discoloration
MBP 2018 -> USB C -> Displayport -> Dell Ultrasharp U2415

On the 2017 MBP the colors work perfectly, but on the 2018 MBP, my letters arbitrarily turn red or blue. See picture below taken with an iPhone. What's going on?

  • Display calibration (basic and advanced) makes no difference
  • Monitor calibration makes no difference
  • When dragging a window, the red/blue/black changes in the characters

Here's a video of the effect on this question if the example below is to blurry.

Actual (taken with an iphone cam, ignore the grid, but notice the red and blue in the letters) :

enter image description here

Expected (yes a screenshot, but the text should be just plain black):

enter image description here

  • The first one looks like you're in so close you can see the individual pixels... the 2nd also has some colour-aberration if you zoom the image, but I think you need to clarify the source of the 2nd image & probably the screen resolution/magnification in both cases.
    – Tetsujin
    Jul 31 '18 at 17:46
  • Right the screenshot is for comparison, the effect can only be captured with an external physical camera. Despite the distortion, you can still see the red and blue where black should be.. these are not artifacts but the actual colors. Surprised that folks with such high rep are missing the point of the question, help me clarify? @Tetsujin Jul 31 '18 at 18:10
  • Added a video, have a look. Jul 31 '18 at 18:18
  • 1
    Just a guess: Go to System Preferences --> General --> and uncheck "Use LCD font smoothing when available" (bottom of the pane).
    – Doc G.
    Aug 1 '18 at 3:37
  • 1
    I got a 2018 MBP a week ago today, so my interest in your question was not idle. As it happens, I purchased Apple's USB-C Digital AV (HDMI) Multiport Adapter along with it, so your report on your experience makes me glad that was my choice. Consider answering your own question with the discovery you made to help others with the same problem.
    – Doc G.
    Aug 1 '18 at 23:07

Go to System Preferences -> General -> and uncheck "Use LCD font smoothing when available" (bottom of the pane). Close all apps and restart your Mac. Then it works for me.


Through some experimentation it seems the only known workaround to me is to switch to HDMI (or some other display protocol).

I don't think the the cable is the problem, because I tried the Itanda and Uni cables on both 2017 and 2018 MBPs. The problem persisted with the 2018 MBPs. I don't think Dell Ultrasharp's are the problem either, because the 2017 MBP and a Lenovo X1 work fine with USBC-Displayport.

Using a USBC to HDMI, the problem went away on the 2018 MBP. This indicates there might be a problem with the 2018 MBP displayport implementation.

  • Agreed, I am also experiencing display issues using USB-c to display port. Sometimes the screens aren't detected, or if they are they switch off and on randomly and don't settle down. I have to unplug one and wait a second then plug it back in and all calms down. Also noticed sound issues occasionally with crackling noises. MBP 2018 sure has some issues right now!!
    – Rob Evans
    Sep 21 '18 at 22:49
  • Yeah! And I have also found that if I plug two monitors in quickly to USBc then the charging cable, the MacBook won’t charge. Sep 22 '18 at 11:43
  • 1
    Sure feels like they rushed this to market!!!
    – Rob Evans
    Oct 9 '18 at 16:36

I Had a similar issue with a new MBP touchbar 2018. Connecting a DVI-D cable fixed the issue for me.

  • It's good to know dvi-d works! Thanks for the added info. Sep 5 '18 at 17:31

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