So you are telling me that rainbows are not real simply because you are unable to see them. Does that mean tables aren't real either because you can't see them? What about apples? Or Joe Biden? Apparently, as you being a blind individual, nothing is real and you live in a world of darkness and nothingness, as do I.
You can taste the rainbow if you eat a bag of Skittles! Anyways, none of your senses tell you that oxygen exists, or the sky, but they have to exist in order for you to live, correct?
Also, a rainbow is a scientific phenomena that happens when sunlight is reflected and dispersed off of water droplets across the sky. Arguing against the reality of a rainbow is quite silly, and you do not need to see it to know that it is real.
Light is made up of all the colors of the spectrum. Since the sun is immensely bright, you are only able to see a blinding, white light. Once the sunlight reaches the Earth's surface, and is reflected off of bodies of water left over from the rain, it is reflected off of all of these water droplets and an arc of a multitude of colors is shown across the sky. Unless you are deaf, you could be able to learn about it in a science class/presentation/etc. It's a phenomena that exists whether you are physically able to see it or not. Just because about 2% of people cannot see a rainbow (or anything, for that matter) does not mean it is completely void of existence and a figment of someone's imagination.