I posted a thread recently with pictures of how much my Martin JDP II had changed colour.
Yesterday I sent these 2 shots to Martin for comment.
Guitar on left is a stock photo of an early build - mine is on the right.
This is their reply;
Hello Bruce,
The tops of our guitars will age a different rates. The amount of exposure to sunlight, humidity , and temperature all need to be factored. Also the quality of the camera and lighting can play a role.