Are my Powerbeat pro's fake?

I purchased my Powerbeats which were a customer return from Amazon warehouse.

I have noticed the 'b' symbol on the right ear is grey, whereas the left ear has a black 'b' logo.

Also the left ear bud has a foam insert in the ear piece and the right one has a metal mesh.

To add to this the left earpiece serial is Apple A2047(China), and the right earpiece serial is Apple A2454(Vietnam).

I'm really asking for confirmation they are a legitimate pair, as I'm pretty convinced they have been swapped and then returned. Can anyone explain what scam I have become victim of?

Thanks in advance.