I have now got a purple colored back side on my black 3GS iPhone!
I discovered the other day that my black Case-Mate iPhone 3GS protector case had reacted with the plastic on the back of my black iPhone. I have not discovered this earlier, probably due to the fact it is much more visible in direct sun light. With in door lightning it is just a tint of different color, compared to the purple colored back of my iPhone in sun light.
The Case-Mate was purchased December 2009 in a Swedish Telenor Store. The case is named “iPhone 3G / 3GS Barely There Cases”
This issue has just been confirmed by a colleague, who has a red Case-Mate case.
Anyone else who have seen this issue on their iPhone?
Below images show the problem. The unaffected area is around the Apple logo, witch is still in original black color. The area outside the circular spot (where the hole is in the CaseMate case) are affected with a purple color tone.