Hello

I'm new to this forum, I hope I'm asking within the right topic.

I'm working with image analysis of CuCl2 crystals, which are affected by different contaminations. In the analysis, the RGB from the scanner is transformed into the Lch-colour space. Within this colour space, I understand that L (lightness) depends on the intensity of the colour and thereby the energy of the light (but relative to the wavelength, as the blue light has a higher energy) and the hue depends on the colour and thereby the wavelength. But I don't understand how the chroma (the saturation, how grey the colour appears) depends on the physical conditions (wavelength, intensity). Can anyone explain it to me?

Many webpages explain the concepts from the human perception, but I need it from the physical/chemical view.

Thanks in advance!