If light is traveling through a medium (i.e. air), the color of light depends on the wavelength.
The following are wavelength intervals of colors on the visible light spectrum. Measured in nanometers (nm).
Red: 700–635 nm
Orange: 635–590 nm
Yellow: 590–560 nm
Green: 560–520 nm
Blue: 490–450 nm
Violet: 450–400 nm