As the mura of a large LED backlight are caused by various factors such as the strength and wavelength of the light emission, light distribution of the individual LED and its structure design, both complicated mura shapes and the affect of hue need to be considered in order to evaluate the white uniformity of an LED backlight. There are no quantitative results showing the relations between human perception and uneven colored characteristic. To quantify the human perception of white uniformity, we used a 40-inch LED backlight to subjectively evaluate white uniformity and found the relation between human perception and physical characteristics from the measurements.