A vehicular dual-state interior rearview mirror assembly includes a mirror head including an electrochromic mirror reflective element having a transflective mirror reflector. A video display device occupies at least 75 percent of the viewable reflective region of the mirror reflective element. With the mirror assembly operating in a first state, the video display device does not display video images and the driver views rearward via reflection at the viewable reflective region and, with the mirror assembly operating in a second state, the video display device displays video images for viewing at the viewable reflective region by the driver. When operating in a daytime mode, the display screen utilizes red pixels, green pixels, blue pixels and clear pixels of the display screen, and when operating in a nighttime mode, the display screen utilizes red pixels, green pixels and blue pixels and does not utilize clear pixels.