E/W STAM Please HELP!

Hello Ladies,

I've purchased an E/W Stam bag in black recently from Bloomingdales then I saw another one at a boutique and the lady offered me a discount so I bought it thinking I will return the first one since I haven't used it yet. I brought it home and looked at them side by side and noticed that the leather color was a bit different as well as the color of the stitching. Upon more careful inspection, I noticed the the tiny white label inside the pocket reads S06 for the Bloomy, and F06 for the boutique's. Every other detail of the bag is the same (chain, lining, name plate, zippers). Was E/W Stam made in spring as well as fall? If so could the bags have been made with a slightly different leather? THANK YOU IN ADVANCE FOR YOUR HELP!!!