This disclosure relates to a display device which includes a light transmissible layer and a second material. The light transmissible layer includes a first material, wherein the first material generates a first color transformation from a first color to a second color after being exposed under a light of the first wavelength range. The second material is either included in the light transmissible layer or has a projective area overlapped with the light transmissible layer. The second material generates a second color transformation from the second color to the first color after being exposed under a light of the first wavelength range.