I begin to see something similar on the Black iPhone 3G S models...
I read this article and I looked at the back. It looks normal under regular light, but under the sunlight, even for a few seconds, I started to see a major "color differentiation" from there. This could be the equivalent of the pink-red color. From experiences, the iPhone 3G S gets warmer faster while the original that I had used previously took at least 20 minutes to actually heat up, faster with Wi-Fi.
Biting the hand that feeds IT
