The yellow screen is NOT a defect, nor is it only refurb units. The yellow screen actually has much better color representation! I have had 4 ip4 and half where yellow half where blue, like said you can't tell unless you compare. I hate the blue looks very washed out ever since the first iPhone. But over time the white balances all look the same. The yellow has a more natural feel, and yes the blue tint seems brighter.
It takes one person to say that the yellow screen is something wrong and people believe it, it's CRAZY how people can convince themselves of that. I currently have a blue tint and HATE it but I'm not gonna get mad or disappointed. But no way it it a PROBLEM.
But I would say a 50 precent chance. And is it that serious of a problem if yours isn't the same as your friends! O NO!