I've been using the LG 43UN700-B for a few weeks now. It's connected to a 16" MacBook Pro (running 10.15.5) for power and video via the USB-C cable that came with the display.
Right from the start, I've been experiencing occasional color glitches. Every 3rd or 4th time I wake the MacBook from sleep, the external display will show very low contrast (like a gray filter applied to the whole image). The MacBook's built-in display is unaffected. Most times, I can get back to normal colors by temporarily changing the external monitor's resolution.
Any ideas what could be causing this and how to fix it permanently? I was unable to find any firmware updates for this display.
Best Answer
Did some more searching through system preferences and the OSD (on-screen display) settings. Looks like high dynamic range may have been the culprit here. After disabling it yesterday, I haven't had any more color issues (usually happens several times a day).