What are the three primary colors detected by the normal human eye?

The three primary colors detected by the normal human eye are red, green, and blue. This model of color perception is based on the trichromatic theory, which states that the human retina contains three types of color receptors, or cones, that are sensitive to different wavelengths of light corresponding to these colors.

The red cones are most sensitive to longer wavelengths, approximately 564-580 nm; the green cones respond to medium wavelengths, around 534-545 nm; and the blue cones are sensitive to shorter wavelengths, approximately 420-440 nm. When light hits these cones, the brain processes the input from all three types to create the perception of a wide range of colors.

Understanding color vision is essential not only in fields like art and design but also in understanding how people perceive the environment around them.