Which color vision theory is primarily utilized by the CIE color system?

The CIE color system primarily utilizes the Trichromatic Theory of color vision. This theory suggests that human perception of color is based on three types of cone photoreceptors in the retina, which are sensitive to short (blue), medium (green), and long (red) wavelengths of light. The CIE system is designed to encompass and quantify how these three colors mix to produce the spectrum of colors that humans can perceive.

In practical terms, the CIE system uses values derived from these three RGB components to create a color model that allows for accurate color representation and comparison across different devices and media. By integrating the outcomes of the trichromatic approach, the CIE color system can effectively communicate color in various applications, such as lighting, paints, and displays.

While Color Opponency Theory describes afterimages and color contrast effects through opposing pairs of colors, it is not the primary foundation of the CIE color space. Color Constancy Theory focuses on the visual system's ability to perceive the colors of objects consistently under varying lighting conditions, which is also outside the main framework of the CIE model. Therefore, the trichromatic basis is the most pertinent theory for understanding the CIE nomenclature and functionality.