Rainbow appears in the sky before and after the rain.Totally there are seven colors in the rainbow
- Red
- Yellow
- Green
- Blue
- Violet
- Orange
- Indigo
Rainbow appears because of raindrops,Rain drops act as prisms and split the sunlight into its colors and produce a rainbow.White light from the sun is the combination of different colors.Each color has different wave length.
Rainbow appeared in curved shape because when light from the sun hit the water drops bends its shape because the index of refraction in water is bigger than that of air. Actually rainbows are formed as circles not arcs,we are only able to see half of the circles.We don't see the full circle of the rainbow because the horizon gets in the way.As the sun goes down we are able to see more of the rainbow,and the higher the sun is in the sky the smaller the arc.