iOS 7 and Color Temperature
iOS devices are calibrated to have cooler white points closer to 7000K rather than the typical 6500K:
(The iPhone 5 has a white point of about 6900K.)
iOS 7 seems to have been designed for cooler displays. On a display calibrated to 6500K, iOS 7's colors look garish. On a display calibrated to 7000K, everything looks more subtle and a lot nicer.