What does he mean no one expected XD ?
I mean you are using still zones. So it is normal that red zones will "red" other colors in that zone XD
Virtually all text, small details will have fucked up colors with such feature and it is impossible to avoid it unless you use white backlight zones which defeats the purpose in the first place.
Bay drapes for windows ?
Or go with normal LCD no RGB baclights, no zones just pure LCD. You won't be looking at pure blacks either way so it doesn't matter.
Also latest OLEDs can peak to 3-4k nits so even in bright room they are good enough.