Our appreciation of the colors of nature is limited by the narrow wavelengths of the electromagnetic spectrum that our eyes can detect. This portion of the electromagnetic spectrum between 390 and 750 nm is what we refer to as the visible (vis) light or, simply, light. We cannot see below (ultraviolet light) or above (infrared light) these wavelengths. Yet this narrow margin of detection allows us to see all the colors of the rainbow, spreading across the visible spectrum from violet (shortest wavelength) to red (longest wavelength). You can see the color palette of visible light in the rainbow up in the sky on a rainy day, as light is dispersed by water droplets. You can also reveal the full color of the visible spectrum using a glass prism: the change of speed of the light as it crosses the glass medium changes the direction of the light waves and enables their dispersion.
Click "source" to read more.