Why is the rainbow made of different colors?

Answer

A rainbow is created when sunlight is reflected in raindrops. You may know that sunlight is a mixture of all colors. Well, in that reflection, the red light is deflected a little less than the green, and the green a little less than the blue. In use here the four “normal” colors, but in reality you also have the mixed colors in between. Each drop thus decomposes a sunbeam into a narrow range of colors and each color is reflected in a slightly different direction.
You can see how this works in figure 1.

Now look at figure 2 : from droplet 1 the red rays reach your eye exactly. The other colors (blue for example) are reflected slightly higher and do not strike your eye. From the direction of this droplet you see red light. Droplet 2, which hangs slightly lower, has the blue color hitting your eye, while the red color does not reach you. In that direction you see blue light. This is how the rainbow is created: each color comes from a slightly different direction.
The red … to the blue light in a rainbow come from other droplets in the rain cloud. The droplets whose blue light reaches your eye float a little lower than the droplets whose red light reaches your eye. This can lead to a difference in height of several meters.

Just search this website for the keyword “rainbow”. You will find a lot of questions and answers regarding rainbows.