A display device, comprising: a plurality of first light emitting elements arranged in a first line and configured for emitting light of a first color; a plurality of second light emitting elements arranged in a second line parallel to the first line and configured for emitting light of a second color different from the first color; and a light emission control unit which is configured to individually control a brightness of each of the plurality of first and second light emitting elements (21-27, 71-77) and to display a display level to be indicated by causing a first number of first light emitting elements, ranging from a first light emitting element arranged at one end of the first line to a first light emitting element arranged on the first line at a first position towards the other end of the first line, to emit light of the first color, characterized in that the display device further comprises a diffusion plate which is arranged at a front side of the plurality of first and second light emitting elements (21-27, 71-77); the light emission control unit is further configured for causing a second number of second light emitting elements, ranging from a second light emitting element arranged at one end of the second line to a second light emitting element arranged on the second line at a second position towards the other end of the second line, to emit light of the second color; said one end of the second line being close to the other end of the first line and remote from the one end of the first line, and said other end of the second line being close to the first end of the first line and remote from the other end of the first line; said first number corresponding to the display level and said second number being selected such that a portion of the diffusion plate at the first position and the second position emits light of a mixed color of the first color and the second color, wherein within the area where the light of the mixed color is emitted a brightness of a predetermined number of the first number of first light emitting elements is decreasing in a direction towards the other end of the first line and a brightness of a predetermined number of the second number of second light emitting elements is decreasing in a direction towards the other end of the second line, thereby creating the appearance of a gradually changing color. a plurality of first light emitting elements arranged in a first line and configured for emitting light of a first color; a plurality of second light emitting elements arranged in a second line parallel to the first line and configured for emitting light of a second color different from the first color; and a light emission control unit which is configured to individually control a brightness of each of the plurality of first and second light emitting elements (21-27, 71-77) and to display a display level to be indicated by causing a first number of first light emitting elements, ranging from a first light emitting element arranged at one end of the first line to a first light emitting element arranged on the first line at a first position towards the other end of the first line, to emit light of the first color, characterized in that the display device further comprises a diffusion plate which is arranged at a front side of the plurality of first and second light emitting elements (21-27, 71-77); the light emission control unit is further configured for causing a second number of second light emitting elements, ranging from a second light emitting element arranged at one end of the second line to a second light emitting element arranged on the second line at a second position towards the other end of the second line, to emit light of the second color; said one end of the second line being close to the other end of the first line and remote from the one end of the first line, and said other end of the second line being close to the first end of the first line and remote from the other end of the first line; said first number corresponding to the display level and said second number being selected such that a portion of the diffusion plate at the first position and the second position emits light of a mixed color of the first color and the second color, wherein within the area where the light of the mixed color is emitted a brightness of a predetermined number of the first number of first light emitting elements is decreasing in a direction towards the other end of the first line and a brightness of a predetermined number of the second number of second light emitting elements is decreasing in a direction towards the other end of the second line, thereby creating the appearance of a gradually changing color.