I did some tests here. Lumia 920 + Amber Update (my father's device). I'm sorry to say, but who have problems with post process need to send your devices to Nokia Care, because I think it's all broken. This time, like Himanshu Chowdhary, I will try to prove my point here:
Real Pics
https://skydrive.live.com/pagenotfounderror
Screenshots
https://skydrive.live.com/pagenotfounderror
So how you guys can see, there's no WB bug, yellowish, green tint or something like that. Believe me, the colours of real pics are little more similar to reality than "saving" screenshots. Real pics have a almost perfect blue, otherwise screnshots have a bad blue. Too bright and exaggerated.
Some of you guys maybe are thinking: "how about sharpness?" Yes, "saving" pictures looks more sharpness. And yes, maybe for some of you it's more beautiful too. But let's make a fair comparison? Because screenshots only have 768p, while real pics have 2000p. 2.6x, right? That's a huge difference. So let's stretch these screenshot for 2000p, ok? That's fair for me.
https://skydrive.live.com/pagenotfounderror
"I don't think this is fair". So how about resize original pics to 768p and compare? That's fair for you? Let's do it!
"Screenshot looks more sharpness and detailed". So you're saying you prefer treated pictures? Because if I treat the original photo on Photoshop (fast treatment), we have the following result:
Did you see now? How exagerated sharpness these screenshots are? There's a name for it: Clarity effect. If you use with discretion, pictures can looks better. It's not the case for me. So It's very controversial prefer sharpness pics if you complaint about how bad Lumia postprocessing are.
So that's it. If you have problems with your 920's camera, MAYBE you have a faulty device. MAYBE, I'm not a professional to guarantee that. But I can guarantee, and you guys can see that now: my fathers 920 have no problem at all with camera.
ps.: Sorry for my bad english.