Let me clear up the Yellow Hue problem.
I'm not an expert, my conclusion is based on my time spent with my old Z1 ( defective screen, Sony service center agreed as well ) and my new Z1.
So here goes:
I bought a Sony Xperia Z1 C6902 around the end of last month. After coming home I almost immediately felt like there was something wrong with the screen.The display light seemed to be coming from the sides ( like underwater divers with lights).I had this yellow hue and slight tilts would produce drastic washing out + more of this mysterious "yellow hue" everyone's been talking about.The display just didn't seem uniform
. Videos and pictures however seemed to display perfectly. A completely white screen would appear patchy.
After a lot of running around, going nuts and tweeting, I finally got my replacement Z1 today.
Now : Slight tilts DO NOT produce drastic washing out anymore.The screen displays uniformly now
.The sharpness of viewing angles still sucks, and there is slight washing out, but only after you're holding it at an awkward angle.
HOW TO CHECK IF YOUR Z1 displays whites correctly.
Do this : Go to your service menu. In your device, open the dialer and enter *#*#7378423#*#* to access the service menu.
Hit Service Tests ---> Display
You will notice the 1st and 2nd screens match the yellow/off whitish tone of the settings menus. ( On a bad screen it will be patchy, on a good screen it will be uniform )
Now tap the screen 8 times
THIS screen will show you if your device displays whites correctly.
(attached pics of my replaced Z1's display test from the service menu )
There are 2 things going on here.The yellow hue and and bad Z1 screens are two different issues, but not completely separate.
The yellow hue /off whitish color seems to be Sony's color config for the Z1.( check the screen i've mentioned above to know if your device shows whites correctly )
The bad screens are the ones that don't display uniformly and seem patchy
,have drastic washing out on slight tilting ( which in turn, seems to make the "yellow hue" seem worse, making people think they're connected.)
Bad Screen : Patchy when displaying a full white screen, drastically bad viewing angles, not uniform, display distortion on even a slight tilt.
Good Screen : Decent viewing angles, NOT patchy when displaying a full white screen, uniform display.
ALL screens seem "yellow".
Sony's customer service here was SO SLOW and It should have happened sooner but after almost a month, I'm finally using the device I paid for.
Trust your eyes. Don't blindly accept that all Z1 screens are bad. The Z1 has a lovely display.Know the difference between the "yellow hue" and a defective screen.
Best of luck !