The biggest misconception is that it has seven colours.
In fact there are millions of colors in it.
Rainbow are completely circular,but only a part of them is visible form the ground.
Rainbow does not look the same the different horizon is different for ever person.Many times,rainbows are also seen forming over the smoking waterfall.
Rainbows are not always formed only by water droplets in the air after rain.
Many times in the world,rainbow is seen even at night which is formed by the light of the moon.
The formation of rainbows is closely related to the angle of sunlight and the high.Rainbows can be double,triple ,quadruple,or even hundreds.