Hope this helps: turn of “Night Shift” when watching movies.

I had this with subtitles. Whenever a subtitle appeared the color became blueish, when it disappeared the color turned to amber.
It took me a while to find out “Night Shift” was the problem. At least turning it off solved mine.

Night Shift can be turned off by clicking in the utmost right corner of the menu bar. On the three horizontal stripes with dashes. This opens the notification center. If you don’t see “Night Shift” on the top of the notification center, scroll the center down.
Other method: Open System Preferences > Open Displays > click on “Night Shift” and turn it off.

Hope I was of any help,
regards Peter