One of the MacOS features is Night Shift. Got to Settings and them Displays. There you can find the Night Shift tab to turn it on or off. I can see a photographer or other graphic artist trying to finalize an important image as the carefully calibrated color managed monitor slows moves into a yellow tint to help you get read for bed. If the morning you go back to the image to get ready to send it our or print it....and wonder why it has a sky blue cast to it.