Why does the monitor flicker when showing a dark image?

Question

Monitors

There is a Lg ul650 4k monitor, today I discovered such a strange thing. I use it with Mac OS. I check for flicker by turning on the iPhone slow motion 240 frames. If I turn on the calendar with a background, then everything is ok, but as soon as I switch to phpStorm, it seems to flicker on its dark Dracula theme.

Can the monitor flicker when displaying only certain colors, how can I check the flicker more accurately?

PS: I checked it on a MacBook without a connected monitor, the same effect, in phpStorm it seems to be flickering on the Dracula theme. In vs code it is similar. The iPhone somehow strangely works with a gray pan in which the code is written

Answer 1

Can the monitor flicker when displaying only certain colors

Rather, when changing the brightness. This is due to PWM .

Answer 2

The description is similar to FRC. Try with this color at different brightnesses, it will be more clear whether it's the color or the backlight PWM (or maybe a combination of these factors).