The Light … beautiful white light. It contains everything. But it also represents the, as the mind might say, boredom of true enlightenment. Nothing spectacular there. Just serenity. Purity. Spotless.
A rainbow gives us a peek into the inner workings. It enables the mind to perceive all the ingredients in that white light by separating them. It induces bliss and amazement by showing the mind all there is that it normally is not aware of since it is used to seeing it all mashed together, perceiving only the end product.
And when do we get this opportunity?
Not when everything is fine. Naturally.
But when on a rainy day, the Light clashes with the grim setting, does not allow it to have the stage to itself. When a ray of hope breaks through in dark times.
The contrast makes us see.
I consider it of profound meaning in connection to this that psychedelic experiences tend to come with perceptions of the rainbow colors.
They make us aware of the full spectrum; of maybe the light at first, but other things later. Time. Space. Experiences. Possibilities.