A signal processing device (200) included in a display which has a color reproduction range larger than that of the input device. The signal processing device (200) comprises color coordinate adjusting unit (210) for performing a color coordinate adjustment for reducing the color coordinates of a video input signal inputted from the input device so as to reduce the variation of the color coordinates caused by the difference between the color reproduction ranges, a luminance adjusting unit (220) for performing a luminance adjustment for reducing the luminance component of the video input signal, a display element control unit (240) for generating a video output signal according to the output of the color coordinate adjusting unit (210) and the output of the luminance adjusting unit (220), and a rate control unit (230) for increasing the color coordinate adjustment contribution rate (β) given to the video output signal by the color coordinate adjustment and decreasing the luminance component contribution rate (α) given to the video output signal by the luminance adjustment if the color saturation of the video input signal with a specific hue is higher than a predetermined threshold.