Question: Why are Rainbows red, orange, yellow, green, blue, purple but not pink?

Zoe Vance answered on 11 Mar 2025:

A physics person might be able to give you a better answer for this but I’ll try!

Different colours of light have different frequencies. You can see different colours because you have receivers in your eyes that respond to different frequencies of light and your brain can decide from the signals what colour you’re seeing. White light is made up of a mixture of all the colours and a rainbow happens when light from the sun is bent through the water in clouds/rain and splits into all the colours so we can see them all. This happens because the different frequencies move at different speeds in the water.

The reason pink isn’t one of the colours we see when that happens is that there is no light frequency that specifically makes pink. Anything we would call pink would be either weak red light or some mixture of the other frequencies.