1. An apparatus for enhancing color of image, comprising: a saturation enhancement unit to enhance a saturation of an input image using a saturation variation according to a brightness feature of the input image, wherein the saturation enhancement unit comprising: a first saturation variation calculation unit to calculate a saturation variation (ΔS mean ) depending on an average brightness value of the input image; and a second saturation variation calculation unit to calculate a saturation variation (Δ pixel ) depending on a brightness value for each pixel of the input image; a gray scale area protection unit to determine a final saturation variation depending on the saturation variation according to the brightness feature of the input image that is determined by a weighted sum between the ΔS mean and the ΔS pixel , and to prevent a saturation enhancement of a gray scale area; a color control unit to control a color of the input image using a color variation according to the brightness feature of the input image; and a brightness value correction unit to correct a difference between a resultant brightness value and an input brightness value of the input image, the resultant brightness value being generated by applying the final saturation variation and the color variation to the input image.