In reality, however, the light is a mixture of various colors such as red, orange, yellow, green, blue, indigo, and purple.
When the light hits the rain particles in the rain clouds, it is divided into its original colors and becomes visible to our eyes. This is because the rain particles of rain clouds work just like a prism. (A prism is a triangular-shaped glass cap that allows us to see light in many different colors.)
Light is refracted at different angles depending on its color. Therefore, when light hits a triangular prism or a prism-like rainbow, it appears to be divided into many different colors. This is the reason why we can see beautiful rainbow colors in the sky.