The light source of the color light box simulates some natural light, and its spectral characteristics are divided into sections. We know that light is part of electromagnetic waves, it has a certain wavelength and contains a certain range of wavelengths. The wavelength range that this light contains is called the light spectrum. The visible light spectrum is from 400nm to 700nm. The visible spectrum of nature contains all the lines in the spectrum from 400nm to 700nm. But the spectrum of artificial visible light cannot contain all the lines in the spectrum from 400nm to 700nm. For example: a three-primary fluorescent tube has only three spectral lines of RGB. The richer the spectral component of an artificial light source, the closer it is to natural light.