An image sensor includes first through fourth pixels. The first pixel includes a first color filter, a first photoelectric conversion device (PD), and a first microlens. The second pixel includes a second PD and a first filling portion. The third pixel includes a third PD and a second filling portion. The fourth pixel includes a fourth PD, a second microlens, and a second color filter different from the first color filter. The second pixel is adjacent to the first pixel. The third pixel is adjacent to the second pixel. The second and third pixels do not comprise any one of a red, blue, and green color filter. Each of the first and second filling portions is configured to transmit light of wavelengths corresponding to blue, red, and green to the second and third PDs, respectively. The first color filter is configured to transmit light of the wavelength corresponding to blue.