Bright HDR Colors after 10.15.4 Catalina Update

just chiming in same issue on LG monitor I fix by consistency hitting toggle until it corrects .. will stay like that while on but once goes to sleep flip back to the crazy neon bright hurt my eyes colors

Same issue with LG 27UL850W on MBP 16" in usb-c. Thanks for the HDR box solution, it's working for me, with the loss of HDR. I tried to make LG calibration software True Color Pro working, but it's not, and it doesn't even recognize the LG Monitor...

No problem in HDMI mode though.

I gave up on the HDMI and only use USB-C - so far no issue on return from reboot / sleep / standby. When did the latest s/w update to OSX I did get a warning "to contact LG as future OS update would not be compatible with the monitor".... I sent a note to LG and got a "what specifically did Mac say"..... I responded with a "Please call Apple yourself and get the new drivers out". Maybe apple just wants us to go to the 5K LG - it is weird because Mac is selling LG monitors in their own stores... sigh

Same problem in August. Clearly not a priority. APPLE PLEASE FIX. You've just destroyed millions of dollars of investment in LG monitors (which you sell at Apple stores). Also odd, my husband and I are both on the most recent version of Catalina and he doesn't have the HDR checkbox when plugged into my monitor. But I do. His colors look great. Mine are terrible. Go figure that one out.

I also have this problem. I am using 2 lg monitors model 27UL850. I am connecting to them through an Elgato thunderbolt doc. Monitors are connected using display ports on the monitors.

One thing I notice is that its not just the color settings, it also sometimes sets the desktop wall paper to a different image. This did not happen until some software update.

I tried the on screen control app. That has not fixed it for me. Hopefully Apple will come up with something.

I just have the 27UL850-W as well, just like many of you, and I am experiencing exactly your problems. Mac OS version 10.5.6; so it has not been solved after the initial problems starting with 10.5.4. I use this script, which runs automatically after login:

https://gist.github.com/adriang133/d0b92a349d097e63a1790a0bfd0eeaf9

However, this works mostly; just like you describe, sometimes you need to toggle 2 or 3 times

Quite disappointing that Apple does not fix it...

You are right, it is definitely not a fix. it is a workaround and if you look into the code it toggles including some timing; so it works slightly better then by hand in my opinion.

==>> APPLE: please really fix it!!!

HOW MUTCH TIME IS NEEDED TO GET THIS FIXED???? This is SOOOOOOOOOOOOOOO annoying, every day I have to toggle this checkbox several times .. right no 5 toggles have been needed!! I have been patient since the first day but now this comes to an end! This crapy story makes me thinking about the "good old days" where I have used Windows. Windows has a ton of other issues, but the Microsoft guys are able to get a screen working. Shame on you Apple!

My setup: 27UK650, MBP 15" 2018 with 10.15.7

Just adding another voice to the calls to Apple to fix this issue. It takes several times checking HDR on and off every day to get the color right with HDR unchecked.

My setup: LG 27UK650-W 27-inch 4K, MBP 15-inch 2017 with macOS 10.15.7

I have now a proper workaround that works, without doing anything or running scripts each time. This is "override EDID". It is described on several sites; being experienced with Linux/BSD, it took me 5 minutes to apply. Since then no issues anymore

https://www.reddit.com/r/MacOS/comments/dkowz1/instructions_for_forcing_rgb_mode_in_catalina/

However, it is ridiculous that this problem is not fixed by Apple since 10.15.4

I have the same issue here. My LG 27UK850 has a grey wash all over the screen with HDR enabled on macOS. After reading this thread, I've disabled HDR. But that's not really a solution, that's just a temporary fix.

Apparently Big Sur finally fixes this!

I lived with this for several months. I've been on Big Sur for about 4 days now and it appears to be fixed. I would have the issue on wake/sleep at least a dozen times a day and it's not done it once since the upgrade.

I will eventually upgrade to Big Sur, but I cannot do it yet until software I depend on fully supports Big Sur. I would have hoped Apple would have a procedure or patch to correct this issue on Catalina.

Man you saved me from huge frustration, just two days back i purchased 27UL850 and when i turned on my monitor it showed colors same as my macbook pro but after sleeping and awake it started showing very vibrant not true colors and i started scratching my head cuz whenever i turn on my monitor it shows hdr msg on right upper left corner, i tried display options but nothing helped and how naive im that i missed HDR checkbox, after reading ur post I noticed this HDR option and turned off mine and everything starts working same way, i know with HDR on screen looks more bright but colors sucks, i edit videos on FCPX and pics on Lightroom and HDR shows so bad colors that u cant even imagine working on color correction, i was thinking of returning the monitor, you saved me from big hassle, lets hope if MacOs Big sir brings some ways so HDR works better with colors, till then the option is off for me.