The light emitted by various sources shows various colors due to the difference in spectral power distribution. Everything in the world has different spectral reflectance (or transmittance), which is why nature appears colorful in the light of the sun. How to express the color of light sources and objects, the following two systems are introduced.
Munsell system is a color classification and calibration system developed by A.H. Munsell according to the visual characteristics of colors. It uses a spheroid model (see FIG. 7.15) to express the three basic characteristics of various surface colors: hue H, lightness V, and chromaticity C. Each part of the diorama represents a specific color and has a label.