Humans see light waves as colors. The specific color is determined by the measurement of the wavelength. On the visible light spectrum, the shortest wavelengths are violet and the longest wavelengths are red.
The color of an object depends on the wavelengths it absorbs and reflects; the visible color is the reflected light wave. The light source can be sunlight, electric light or light from a flame. Cones in the eye receive the light waves and translate them into color information for the brain. Visible light is the only type of electromagnetic radiation that is visible to the human eye.