What is "pentachromacy"

n. The quality of having five independent channels for conveying color information in the eye.

Pentachromacy describes the capability and capacity for capturing, transmitting, processing, and perceiving five independent channels of color information through the primary visual system. Organisms with pentachromacy are termed pentachromats. For these organisms, it would take at least five differing ranges of wavelengths along the electromagnetic spectrum to reproduce their full visual spectrum. In comparison, a combination of red, green, and blue wavelengths of light are all that is necessary to simulate most of the common human trichromat visual spectrum.

One proposed explanation for pentachromacy is a retina containing five distinct types of cone cells with differing absorption spectra. In actuality the number of cone cell types may be greater than five as different types may be active at a specific intensity or range of intensities for a given wavelength of electromagnetic radiation.