A ray of light from the Sun, or from an electric light bulb, looks white. But this white light is really a mixture of lights of different colours! To see these colours, we must split up the white light by shining it through a glass ‘prism’.
White light is refracted as it enters and leaves the prism. Different colours of light travel at slightly different speeds through the glass. As they leave the prism, they bend different amounts. The colours red, orange, yellow, green, blue and violet can be seen. They’re called the ‘spectrum’. We can see the colours of the spectrum naturally in soap bubbles, thin films of oil or rainbows.
You can make white light by mixing light of different colours together. A spinning wheel is divided into equal sections. Each section is painted with a different colour from the spectrum. As the wheel spins, the colours ‘mix’ together and the wheel looks white!
White sunlight may be split into the colours of the spectrum by raindrops. White light bends as it enters the edge of the water droplet. It is then reflected back into the drop and is bent once more as it leaves the drop. The colours of the spectrum are now spread out. Thousands of raindrops together may separate sunlight in this way and form a rainbow, one of the most beautiful natural sights of all.
The colours of the rainbow range from red on the outside to violet on the inside.
Picture Credit : Google