Strictly speaking, the color impression arises from the reflection and absorption of certain wavelengths of the electromagnetic (wave) spectrum from light on a body (object). Without - or little - light, no color (at night, all cats are gray). One could understand it as a filtering process. The green color impression, for example, arises from the reflection of the green "components" (wavelengths) from, for example, sunlight. If the light mixture does not contain the corresponding color, e.g. incandescent light, that part cannot be reflected either. In the case of white, almost all components of the light are reflected; in the case of black, almost all components are absorbed, and the body heats up more as a result. In some representations, therefore, white, black, and gray (partial reflection/absorption of almost all components) are not considered colors in the strict sense. In other representations, they are referred to as so-called neutral colors.