ISO 3664 defines Chromaticity as the “property of a color stimulus defined by its chromaticity coordinates, or by its dominant or complementary wavelength and purity taken together.” The apparent color of a light source, specified by its three chromaticity coordinates. Since the human eye has three types of color sensors that respond to different ranges of wavelengths, a full plot of all visible colors is a three-dimensional figure. The aim-point and tolerance are specified in CIE color space. When two viewing systems are plotted, the closer the plot, the greater the visual agreement between the viewers’ color appearance. However, the concept of color can be divided into two parts: brightness and chromaticity. For example, the color white is a bright color, while the color grey is considered to be a less bright version of that same white. In other words, the chromaticity of white and grey are the same while their brightness differs.