Colour management/correction is done by the computer without involving the monitor afaik.

But I have a suspicion what might be causing your issue.. Computers can indeed control monitor settings such as brightness and power on/off through something which I believe is called DDC/CI (in case you wanna search for more information). When I bought a new Dell monitor I got an issue where it would randomly change brightness every now and then. I have my Linux PC hooked up to 2 monitors, and my work Windows laptop also connected to one of them. So while I was working, my own PC would think that I was idle and dimmed the screens. However, unlike my old monitors, the Dell would accept DDC/CI commands on all connections, not only the selected one. I just turned off monitor dimming in KDE control panel power settings as a workaround, and let it turn the monitor signal off immediately on inactivity.

While researching the issue, I also came across multiple posts by people having problems with Dell monitors randomly changing brightness, with only one computer connected, so it could also be that.. Dell has a reset procedure which they claim should fix it, but it's different for pretty much every model, so you'll have to find the one for yours, in case you have a Dell monitor. Some people wrote that it didn't work and they had to RMA the monitors.