A rainbow is nature’s example to show that sunlight is made up of different colours. A rainbow is formed in the sky because of the dispersion of sunlight by millions of water droplets in the atmosphere. Every single water droplet behaves like a tiny glass prism that splits the white light into different colours. Different colours bend at different angles on passing through the water droplets, thus separating the white light into a natural spectrum of seven colours, namely, violet, indigo, blue, green, yellow, orange and red.