I repeat it again.
The iPhone 7 has a warmer screen than iPhone 6/6s.
This is the new DCI-P3 Panel, wich is a professional, right calibrated display.
http://displaymate.com/iPhone7_ShootOut_1.htm
Its all in your head.
I was used to my iPhone 6 for 2 years and I thought it was "white" and normal.
Now after 4 days of using my iPhone 7 its white and normal too.
But if I take my iPhone 6 now, i clearly see that it has a massive blue-tint and looks not natural like the 7 does.
I made some more pictures with my DSLR.
Pictures are taken at morning on my bed, both phones lying in direct harsh sunlight coming from the window.
You can see on the top edges on the phones that the light is really harsh.
To my eyes, the iphone 7 is clearly brighter, more natural and better readable.