Hierarchy of Colors

The frequency of light wave refers to the number of waves that move past a certain point in one second. Frequency is generally measured in Hertz, the units of cycles per second. Color has the frequency ranging from 430 trillion Hertz to 750 trillion Hertz. Waves can also go beyond and below those frequencies, but they are not visible to the human eye.

Wave frequency is related to wave energy. The more energy in the wave, the higher its frequency. The lower the frequency is, the less energy in the wave. When it comes to light waves, violet has the highest energy while red has the lowest energy. Related to energy and frequency is the wavelength, or the distance between corresponding points on subsequent waves. You can measure wavelength from peak to peak, trough to trough or between two consecutive corresponding points of waves. 

Within the band of visible light, the different wavelengths are perceived by people as different colors. The shortest wavelength is violet, and the longest wavelength is red.