Rainbows are often seen when the sun comes out after or during a rainstorm. Rainbows are caused when sunlight shines through drops of water in the sky at a specific angle. When white sunlight enters a raindrop, it exits the raindrops at different angles, it produces the red, orange, yellow, green, blue, indigo, and violet that you see in a rainbow. Together, these colours are known as the spectrum. These colours can sometimes be seen in waterfalls and fountains as well.

Did you know that there are double rainbows? In a double rainbow, light reflects twice inside water droplets and forms two arcs. In most double rainbows, the colours of the top arc are opposite from those in the bottom arc. In other words, the order of colours starts with purple on top and ends with the red on bottom. Believe it or not, rainbows sometimes appear as white arc at night. These rainbows are called moonbows. Moonbows are caused by moonlight (rather than sunlight) shining through drops of water.