I believe I have already suggested that colour is the most obvious bridge between emotion and perception, that is, between subjective experience of the psyche and quality objective in nature. Both light up only between the extremes of light and darkness, and in their reciprocal interplay. Thus, outward the rainbow–or, if you prefer it, the spectrum–is the bridge between dark and light, but inwardly the rainbow is, what the soul itself is, the bridge between body and spirit, between earth and heaven.
~ Owen Barfield
When I set a glass prism on a windowsill and allow the sun to flood through it, a spectrum of colors dances on the floor. What we call “white” is a rainbow of colored rays packed into a small space. The prism sets them free. Love is the white light of emotion.
~ Diane Ackerman
If you have ever followed a rainbow to its end, it leads you to the ground on which you are standing.
~ Alan Cohen