Because rainbows are happy and gay, right? :)
Just curious...when you say they don’t understand the significance of the colors of the rainbow, what do you mean? From a physics/light spectrum standpoint? Because now I’m sitting here thinking: “Wait...are they significant in a way that I don’t understand?” All I know about the significance of the colors themselves is light frequency. Is there something else? I love learning new things.
Couple things.
A rainbow is actually not discrete, but has the full range of wavelengths spread out. If you have a non-colourized camera, you will see this in the shots.
What the eye sees in a rainbow are distinct bands that represent different sensitivities in the eyes. ROYGBIV. There’s reasons for each one that can be explained as to why it was important for the eye to distinguish between each one.
Now,try teaching optics to someone who’s never been taught that the difference between red and green is simply the wavelength of the light. First year student in college, and I swear I am telling the truth, had never been taught that colours correspond to different wavelengths.