Monitor issues

[holyzombiejesus]

My monitor (LG 23MP75, about 7 years old) is getting on my nerves. It keeps slightly changing the screen colour by turning the brightness down. Wouldn't describe it as a flicker as the changes are only every 30 seconds at most but it's really irritating. I've tried going in to the menu but it's not had any effect (although I am useless when it comes to this kind of thing and, computer-wise, illiterate). Any ideas?

[seepage]

Does it have an 'ambient mode' that adjusts with the light? If so you could try turning that off in the settings.