How would you describe a rainbow in a poetic way?

I like fooling around on Quora.

Describing rainbow is tricky because it is an abstract thing that is interpreted differently by everyone. Basically, you can’t really describe a “rainbow”, you need to describe something related to rainbow that can be relatable to the reader.
In other words - not write about rainbow, but write around rainbow.
That’s one way of doing it.
However, if we take a step further and try to actually describe the thing - there are several things to note.

• rainbow can’t be described by ordinary words. It will neuter its impact.
• rainbow description doesn’t really work with specialized terms. It sounds cool, but it can be as well just some glossolalia.
• old and rarely used words can’t make it justice.

Then there is more technical approach. Since poetry creatively uses language and its nuances - the thing can be deconstructed and described from the inside out. Since regular color names are boring - there must be the other way around. For example, you can use Hex Color Designations.
To my taste - this is the most aesthetically intriguing and poetic way of describing a rainbow. At the very least - it will be much more interesting than just throwing some nice words and getting the “feels” out of it.
On the other hand, you can make it a conceptual thing and describe rainbow the optical phenomenon with the elements of a creative out of Rainbow the band.