I'd argue that it's because of the wallpaper.
SAMOLED tends to over-saturate (this is different from having higher color gamut, by the way) contents on the screen in my experience, and it makes blue more blown out than necessary.
I agree that it does hurt my eyes, but you can easily change the wallpaper to something else.
And unless you look at blue stuffs on your phone all day long, I don't think it should be a concern.
The screen still displays a white page with some hints of yellow, in case you wanna know what I meant when I said the display was "warm".
It's just "blue" that is overly... "blue" on those SAMOLED displays IMO.
The wallpaper? It looks like an overlay of blue.