Color issue with mac mini and Dell S2719DM

Hexley1

macrumors newbie
Original poster
Mar 13, 2019
8
1
New Jersey
I recently picked up a 2018 Mac mini and two Dell S2719DM monitors. I noticed the monitors would wake up and turn purple sometimes. After a lot of troubleshooting I realized the dell monitors are in YPbPr color mode and not RGB. I spoke to Apple support for about two hours and then Dell. I really didn't make any progress with any either support call. I've tried 3 different adapter, different high-end HDMI cables, as well as running the monitor directly into the HDMI port. I did find a few videos on running scripts into the terminal forcing the video output to RGB, but I really don't want to get into that mess of messing with the OS.

Does anyone else have this issue with using the Dell S2719DM monitors? I'm wondering how off the colors are in this mode. The Dell told me this mode is fine even though the manual says this mode is for DVD players. The monitors will only look normal in YPbPr mode not in RGB mode. When in RGB mode the monitors turn purple. The dell monitor is reporting the wrong EDID information to the mac.

YPbPr = Designed for a DVD player that only has the YPbPr output
RGB = Computer or DVD player using HDMI or DP
I purchased these monitors for mainly watching videos and editing photos for the web.
 

Ruggy

macrumors 6502
Jan 11, 2017
250
154
I would love to help but I can't quite see the problem.
Does the Mac output RGB and does the Dell accept that it's RGB but then shows over saturation turning purple? Or does it think it's YPbPr?
It should be possible to run the monitors in RGB but you would have to configure it as such through the buttons on the front, not rely on it being picked up automatically.
You shouldn't 't see much difference in colour but if it runs purple in RGB then you need to change the colour saturation on the monitor down from 100% (or luminance probably). Through the controls on the front of the monitor once more.
You must have tried that so I guess it can't be that simple and I haven't understood.
[doublepost=1562861601][/doublepost]
I would love to help but I can't quite see the problem.
Does the Mac output RGB and does the Dell accept that it's RGB but then shows over saturation turning purple? Or does it think it's YPbPr?
It should be possible to run the monitors in RGB but you would have to configure it as such through the buttons on the front, not rely on it being picked up automatically.
You shouldn't 't see much difference in colour but if it runs purple in RGB then you need to change the colour saturation on the monitor down from 100% (or luminance probably). Through the controls on the front of the monitor once more.
You must have tried that so I guess it can't be that simple and I haven't understood.
Note: I just found this.

https://www.tomshardware.com/reviews/dell-s2719dm-qhd-hdr-monitor,5655-2.html
 

Hexley1

macrumors newbie
Original poster
Mar 13, 2019
8
1
New Jersey
When you use the on-screen display (OSD) on the monitor and select RGB mode the image turns purple. Switching to YPbPr mode makes the purple cast go away. This means the Mac mini isn't outputting RGB and doesn't see the Dell monitor as a monitor. The mac mini thinks it's a TV.
 
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bbednarz

macrumors 65816
Nov 16, 2017
1,161
2,698
Chicago
I have this issue with my 2014 MBP. I figured it was my cable or something. I'm outputting to 2 29" LG ultrawide monitors though... Maybe it has something to do with this RGB stuff you mentioned.... Weird that it only happens every now and then too. Have to turn the monitor off/on to get the colors corrected.
 

Hexley1

macrumors newbie
Original poster
Mar 13, 2019
8
1
New Jersey
I brought home a MacBook Pro (15-inch, 2018) last night to test it with the Dell S2719DM. The macbook does the same thing as the mac mini. You can't run either device in RGB mode.
 

Ruggy

macrumors 6502
Jan 11, 2017
250
154
When you use the on-screen display (OSD) on the monitor and select RGB mode the image turns purple. Switching to YPbPr mode makes the purple cast go away. This means the Mac mini isn't outputting RGB and doesn't see the Dell monitor as a monitor. The mac mini thinks it's a TV.
Yes but you might also get a purple image if the blue and red are over saturated on the monitor. Have you tried adjusting the settings on the monitor? If it's two machines doing it and it's not usually a problem, isn't it more likely to be something on the monitor?
 

Sarpanch

macrumors member
Jan 12, 2013
84
67
SoCal
Thanks for sharing this! Surprisingly my Dell U2518D monitor was running on YPbPr 59.97 Hz all this time but with no apparent difference. If I connect it via DP, it detects the monitor with RGB.

I used the guide pasted in this link and now the Mini detects it as RGB 60Hz. Surprisingly, after making this change, I am not facing the issue of monitor losing signal during boot up which was happening almost 50% of the times
 
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Fishrrman

macrumors P6
Feb 20, 2009
17,200
5,547
OP wrote in reply 3 above:
"I came across this page earlier; It's almost 6 years old. It seems like a cumbersome process."

It still works, and it's relatively easy to implement.

I suggest you give it a try before going further.
Then get back to us with your results.
 

vpvasquez11

macrumors newbie
Sep 25, 2015
9
5
I have this exact set-up and I am not experiencing what you are. I plugged both monitors in (one via HDMI and one with an HDMI to USB-C cable) and both worked from the start without any modifications to the settings, on the mini or the monitors.