Wavelengths and Colors

The human eye sees color over wavelengths ranging roughly from 400 nanometers (violet) to 700 nanometers (red). Light from 400–700 nanometers (nm) is called visible light, or the visible spectrum, because humans can see it. Light outside this range may be visible to other organisms but cannot be perceived by the human eye. Colors of light that correspond to narrow wavelength bands (monochromatic light) are the pure spectral colors learned using the ROYGBIV acronym: red, orange, yellow, green, blue, indigo, and violet.

The wavelengths of visible light are:

Violet: 380–450 nm (688–789 THz frequency)
Blue: 450–495 nm
Green: 495–570 nm
Yellow: 570–590 nm
Orange: 590–620 nm
Red: 620–750 nm (400–484 THz frequency)

Violet light has the shortest wavelength, which means it has the highest frequency and energy. Red has the longest wavelength, the shortest frequency, and the lowest energy.