Time stability, uniformity, color gamut, chromaticity constancy, and channel independence of iPhone 4S were tested. The color characteristics of iPhone 4S were described quantitatively. The impact of color characteristics of iPhone 4S on displaying color image and the way to get the best color performance was analyzed. The results showed that iPhone 4S has good chromaticity constancy, but the color gamut is low; the accuracy in displaying high saturated color is not enough; better color performance can be acquired when adjusting to medium or high luminance range.