Like i said before, you should take your time and check your new phone condition first before you take it home. Quite a few cases of defect comes from the screen.
No need to get gray wallpaper. You can do a scrern test by using dialler code *#0*#  :-P

as far as i know, no 2 amoled screens are made the same, but here's the bad news, amoleds are made blue-er than usual for a special reason, the organic substance inside the amoled will degrade with usage , so if yours is yellower it means your amoled screen is more degraded than your friend's, which also explains why his is brighter, but there shouldnt be such a huge difference, if really obvious, go and replace it

nice explaination there... are u sure of that?
but to me, my fren's looks much better, screen brighter... anybody faces the same prob?

please get your facts right, in an amoled display the blue o-led will degrade the fastest among the other colours(you can easily google or wiki it). Which is why all oled screens are bluer than normal, so that when it degrades the loss in blue isnt so obvious, common sense, blue fastest, make blue more, so you will get more or less the same colour tones later on, and not yellow-->yellower-->dam yellow the loss of blue o-led's brightness also contributes to his loss of brightness

sure you can say u have a yellower oled unit but when the time comes and your blue oleds brightness goes down alot you'll see the big problem, its up to ur choice tho, not many ppl even know about these, but if i were u i would have exchanged it, everyone blue and ur yellow? doesnt sound right to me

extract from wikipedia

http://en.wikipedia.org/wiki/Organic_light-emitting_diode
+1

did you read the second disadvantage? read my previous post i even bold it for you  that doesnt change the fact that blue o-leds still degrades the fastest and is still the current problem. Our unit shows bluer is bcoz samsung made the s-amoled screens like that, not bcoz it's adjusted in the settings or what, it's made that way, what is shown is just an experimental oled, you actually think it's accurate? what more, we're using s-amoled+ not an experimental o-led i doubt it will have 62 hours of lifetime, if so, then samsung can go bankrupt ad  screens lightbulbds are all made to last a specific time, if light bulbs can last 100yrs then philips will go bankrupt also, there is a record where a lightbulb managed to last 82 years, then why our lightbulb half a year kong ad? samsung must have its reasond . the blue tint while off angle i also cant confirm la, its oled or its the glass la...

anyways, what i'm concern is, you shouldnt advice the dude to be happy with a yellow device, he said bought same time, maybe his unit's flawed? maybe his unit's blue oled degrades dam fast? how? ask him be happy, no way right?

hahas okok maybe i read wrong, so he shud go either one, well to me the blue is what it should be and the yellow is defective, up to him to decide ba, my assumption was, (low brightness+yelllow)=blue oled degrading a whole lot faster than normal 

Or you can keep the yellower screen with wide viewing angle and use CF3D's nightmode settings to tune colour to whatever side of the spectrum you want.

Sure, if you're yellowish it means that your bluesubpixes are dying, and tuning the display blue will just make it die off faster (lol), but at least you can if you wanted to.