Sunlight has the enormous speed of 300,000 km/second, covering particular wavelengths and is the sum of seven different colours.
Rainbow in the sky is a wonderful spectrum of colours. Water drops suspended in the air on which sun’s rays fall act as prisms, which break up the white light into its component colours. Thus, we frequently see a rainbow after heavy rain and storm.
Below Rainbow info from Wikipedia (Read More):-
A rainbow is an optical and meteorological phenomenon that causes a spectrum of light to appear in the sky when the Sun shines onto droplets of moisture in the Earth's atmosphere. They take the form of a multicoloured arc, with red on the outer part of the arch and violet on the inner section of the arch.
A rainbow spans a continuous spectrum of colours; the discrete bands are an artefact of human colour vision. The most commonly cited and remembered sequence, in English, is Newton's sevenfold red, orange, yellow, green, blue, indigo and violet (popularly memorized by mnemonics like Roy G. Biv). Rainbows can be caused by other forms of water than rain, including mist, spray, and dew.
http://en.wikipedia.org/wiki/Rainbow
