I got my 1 to 1 exchange from Huawei service center on Monday. Some thought to share, the manager at the service center, base on my experience, though he speak quite loudly & seems impatient, but to be fair, at least he try his best to explain the common feedback and try hard to be polite. Some of the complaint is quite unreasonable, but Huawei still provide the swap without any detailed checking on the device to make the customer happy with the purchase. I waited 2 weeks for my exchange unit too.
My first unit has unbalance white (blueish on top, yellowish at bottom), new unit have balance white (quite yellowish tho). I think it's true that google or Huawei made the nexus 6p to display yellowish white, and the color does change to blueish a bit when tilted, to me I'm fine with this as I think it's the characteristic of LED as compared to LCD.
There's an app name 'Screen Adjuster Free' in apps store which help to tune the color, I think some bro here using it, I notice the app request permission to get location, contacts & phone, not sure why it request for it, I revoked those permission from it, feel stealthy.