In my latest video, Judaism vs. Buddhism - Hinduism I said that a famous Indian guru wrote that the "blue light" was the highest vision possible, but Jewish mystical sources say that it is the lowest color. These Jewish sources warn that the color blue in visions is to be completely avoided, and that we should pray hard not to see it!
A number of people have challenged me on this:
"If blue is the lowest color, why are so many houses and grave stones in Safed (a holy city in northern Israel) painted blue?"
"What about the blue thread on the fringes?"
"There was sapphire (blue) color in Ezekiel's vision under the throne of Hashem. So how can you say that blue is the lowest color?"
My response: The Zohar Chadash teaches that the color blue is the lowest color in visions not on walls.
As to the custom in Safed, and some other places, to paint grave stones or even walls blue; while the people who do it might claim that it signifies importance, or even that it is a defense against the evil eye, there is no Torah source for such thinking. Some go as far as to claim that since blue is the color of water, and fish live in water, and fish do not close their eyes, therefore blue is a defense against the "evil eye." To my knowledge, no Torah source entertains such thinking. The so called "evil eye" in Torah refers to someone doing something in such a way as to draw attention to himself, and with it the dangers of publicizing one's self needlessly.
As to the blue thread on our fringes; blue was also used in part of the High Priest's garments when he served in the Temple.
The fact that the sapphire color appeared under the throne in the vision shows that the blue color is lower.
For our purposes; look at a flame and see that the color blue is always at the bottom. When light shines through a prism blue is on the lower side of the spectrum. Our search is not for the colors, and surely not for the lower colors, but for the light. In this metaphor, the colors represent the multiple creation, and the light represents the universal from which all things come. So in this illustration, although all of the colors are made out of the one light, focusing on the blue (the darker colors) will take your attention the furthest away from focusing on the light.