...like grey colours? If you look at the black image from the sides, yes!

Is HDR activated there by any chance? Because if I don't activate HDR in the monitor itself, everything on my computer monitor is grey when HDR is activated in Windows 11. But as soon as I activate HDR on the monitor in the settings, the colours are displayed correctly. Is it possible to switch HDR off and on in the monitor? I don't have the ROG Swift, but my monitor can switch HDR on and off in the menu.

Maybe you could also test it with a different connection cable, e.g. DisplayPort if HDMI shows a grey haze or vice versa?

okay i tried to adjust the monitor again today so the colours seem very dark and the edges seem very dark to me as well.