Question

why are only 7 colors[vibgyor] present in the rainbow

Answer 1

Rainbow is formed by the dispersion of white light by the water droplets present in air. We know White light is composed of seven different colors commonly dented by the famous acronym VIBGYOR.

Here letters represent different colors

V - violet

I - indigo

B - blue

G - green

Y - yellow

O - orange

R - red