As humans, we perceive the sensation of color based on the stimulation of different types of photoreceptor cells in our eyes called cones. Cones are sensitive to different ranges of wavelengths, allowing us to perceive different colors.
In the normal functioning of our visual system, when we view a single wavelength of light, it typically corresponds to a specific color sensation. For example, if we view a light source that emits light at a wavelength of 550 nm, we would perceive it as green.
On the other hand, when multiple wavelengths of light are superimposed at the same location, our visual system integrates the signals from the different cones and we perceive a combined color sensation. This is known as additive color mixing.
The perception of color in the case of multiple superimposed wavelengths depends on the specific wavelengths and their intensities. If the superimposed wavelengths correspond to the primary colors (red, green, and blue), our visual system can perceive a wide range of colors through additive color mixing. This is the principle behind how color displays, such as computer monitors or TVs, can create a wide gamut of colors by combining different intensities of red, green, and blue light.
However, if the superimposed wavelengths do not correspond to the primary colors or specific combinations that our visual system is familiar with, the resulting color perception may be more difficult to predict or interpret. The specific interactions between the wavelengths and the relative intensities can lead to various color perceptions, including colors that may not exist as single wavelengths of light.
In summary, our visual system can perceive single wavelengths of light as specific colors, while multiple superimposed wavelengths can lead to additive color mixing and the perception of a combined color sensation, influenced by the specific wavelengths and their intensities.