We developed color filtering functional organic thin-film transistors exhibiting both high field-effect mobilities and color-filtering ability. The conventional colorant inks were utilized as the materials for the color filter/dielectric multifunction layers. In order to improve the electrical performance, a high dielectric polymeric insulator, poly(2,2,2-trifluoroethyl methacrylate), was introduced to modify the surface of the dielectric layer. Further, the Commission Internationale de L'Eclairage chromaticity coordinates were (0.64, 0.34), (0.36, 0.54), and (0.14, 0.15) for red, green, and blue devices, respectively, covering 49.2% National Television Systems Committee standard. This work represents one potential example for multifunctional organic electronics.