You make an interesting point about perception. I would be curious to know how many of the folks who feel that their iPhone 5 looks yellowish, have the black phone vs. those who have the white.
The reason that I mention this, is that I own a white phone. When the phone is off, the body/bezel looks quite white against the black screen. But when I turn the phone on, the body/bezel looks somewhat creamier colored in comparison to the display, which I find somewhat blueish.
The blueish tint would make sense following the findings of DislayMate.com report/comparison I linked to in my previous post. They report the iPhone 5 display as "7461 degrees Kelvin, Somehwhat to Blue." Which of course is not yellow-ish at all, except when compared to the 4S which is 7781 Kelvin, somehwat more blue than the iPhone 5. 321 Kelvin, when compared side by side is noticable.
My Laptop, which I have set to change to a 6200 degrees Kelvin at night via the Flux utility, looks conciderably more yellow than my iPhone 5 at 7461 degrees Kelvin. Playing with Flux, and going back and forth between 6500 Kelvin and 6200 Kelvin, i find that 6200 Kelvin looks significantly yellower. But in actuallity, 62000 Kelvin is still fairly blue/white as well. The color scale doesn't really begin to get yellow/white until about 5000 Kelvin.
http://soultravelmultimedia.com/wp-content/uploads/2010/04/colour-temperature.jp g
So I do have to wonder how much perception plays a role in the yellow appearance. 7461 Kelvin is actually a fairly blue/white.