The visible portion of light is that portion of the electromagnetic spectrum which is detectable by the human eye. Light from the sun appears to be white to the human eye because it contains all visible colors. The Visible portion of the electromagnetic spectrum is only a small part of the entire electromagnetic spectrum emitted by the sun.
The wavelengths of visible light is in the range of approximately 3900 to 7800 Angstroms, where one Angstrom is 0.0000000001 meters (1×10−10 m). These wavelengths correspond to frequencies of between 400-790 GHz. The visible spectrum is most obvious in a rainbow, where the sun's different colors of light are bent (refracted) by the earth's atmosphere during a rainstorm and separated into the wavelengths of which white light is composed.