A liquid crystal display device comprising: a liquid crystal display panel having a pixel defined by a plurality of subpixels, wherein the plurality of subpixels are a red subpixel to display red, a green subpixel to display green, a blue subpixel to display blue, and a yellow subpixel to display yellow; and a driving circuit adapted to supply display signals to the plurality of subpixels of the liquid crystal display panel, the driving circuit is adapted to supply display signals of a same grayscale level to a first subpixel group composed of two subpixels when achromatic colors of at least some gray levels among all gray levels are to be displayed by the pixel, wherein said first subpixel group of two subpixels is composed of the yellow subpixel and either the red subpixel or the green subpixel, respectively, and the driving circuit is adapted to supply display signals of a grayscale level to a second subpixel group composed of two subpixels when achromatic colors of at least some gray levels among all gray levels are to be displayed by the pixel, wherein said two subpixels of said second subpixel group are subpixels other than the two subpixels of the first subpixel group, and are composed of the blue subpixel and either the green subpixel or the red subpixel, respectively, and wherein the grayscale level of the display signals supplied to the second subpixel group is different from said grayscale level of the display signals supplied to the first subpixel group; characterized in that with respect to an achromatic color of a given intermediate gray level among the at least some gray levels being displayed by the pixel, xy chromaticity coordinates of an achromatic color displayed by the pixel when assuming that display signals of the same grayscale level as the given intermediate gray level are supplied to all of the plurality of subpixels is defined as a reference chromaticity point; xy chromaticity coordinates of an achromatic color of a highest grayscale level displayed by the pixel is defined as a target chromaticity point; and a locus of the reference chromaticity point on an xy chromaticity diagram when the grayscale level of the display signal supplied to the blue subpixel is increased or decreased is defined as a B axis; when the target chromaticity point is located above the B axis on the xy chromaticity diagram, the first subpixel group further includes the red subpixel, the second subpixel group further includes the green subpixel, and the driving circuit is adapted to supply a display signal of a lower grayscale level than the grayscale level of the display signals supplied to the yellow subpixel and the red subpixel to the blue subpixel, and the driving circuit is further adapted to supply a display signal of a higher grayscale level than the grayscale level of the display signals supplied to the yellow subpixel and the red subpixel to the green subpixel; and when the target chromaticity point is located below the B axis on the xy chromaticity diagram, the first subpixel group further includes the green subpixel, the second subpixel group further includes the red subpixel, and the driving circuit is adapted to supply a display signal of a lower grayscale level than the grayscale level of the display signals supplied to the yellow subpixel and the green subpixel to the blue subpixel, and the driving circuit is further adapted to supply a display signal signal of a higher grayscale level than the grayscale level of the display signals supplied to the yellow subpixel and the green subpixel to the red subpixel is a display. a liquid crystal display panel having a pixel defined by a plurality of subpixels, wherein the plurality of subpixels are a red subpixel to display red, a green subpixel to display green, a blue subpixel to display blue, and a yellow subpixel to display yellow; and a driving circuit adapted to supply display signals to the plurality of subpixels of the liquid crystal display panel, the driving circuit is adapted to supply display signals of a same grayscale level to a first subpixel group composed of two subpixels when achromatic colors of at least some gray levels among all gray levels are to be displayed by the pixel, wherein said first subpixel group of two subpixels is composed of the yellow subpixel and either the red subpixel or the green subpixel, respectively, and the driving circuit is adapted to supply display signals of a grayscale level to a second subpixel group composed of two subpixels when achromatic colors of at least some gray levels among all gray levels are to be displayed by the pixel, wherein said two subpixels of said second subpixel group are subpixels other than the two subpixels of the first subpixel group, and are composed of the blue subpixel and either the green subpixel or the red subpixel, respectively, and wherein the grayscale level of the display signals supplied to the second subpixel group is different from said grayscale level of the display signals supplied to the first subpixel group;