Originally Posted by
AlwaysSunnyInORD
I assume we are talking about for an iPhone. Mine started as blue but changed to black once I obtained status (through a Platinum Challenge).
This explains my experience. I'm a US elite, and earlier in the year, I initially get blue passbook BP, but then it switches a few moments later to black, with PA (Priority Access). Has happened quite a few time, but not anymore, so PA/non-PA was my (educated) guess.