Blue.

I used to hunt for sea-sand smooth fragments of glass on beaches when I was a child.

Blue glass was rare, a transition element.
Washed from the land of death up onto the beaches of childhood; safely glittering under the sun.

Blue glass was the best;.

They said it came from poison bottles.

I wear blue glasses.
And I see that there is a new mythology of blue being written before my very eyes.

For instance, YouTube brings me an image of a man with dyskinesia able to walk only when staring at blue, or wearing blue lenses. 

In Stephen King's story Room 1408, blue light elucidates a terrible truth as traces of human fluids glow under the blue.

Blue light is supposed to make body fluids light up.
Does it?

Here is the Norway spiral
kinda blue.


And here is a light installation called Red and Blue:




Blue light.
Wide blue yonder
Light.

There is the tale of the Steel melter's blue spectacles:

The precise shade of [blue] glass varied from one pair to the next and so steel melters carefully guarded their own pairs as they'd be unable to accurately judge the condition of the melt if another man's spectacles were used. This was one of the last bastions of a 'black art' i.e. a skill that could only be learnt by years of experience.

Blue spectacles are sold as dieting aids, the theory being that blue food is usually moldy "blue hue acts an appetite suppressant, because few foods are naturally that colour". 

Professor Stein suggested that blue lenses filter out the wavelengths of light that disturb cells in the brain damaged by an auto-immune disorder in the womb. 

He goes on to say that blue light improves sleeping patterns, because the blue-sensitive cells communicate, not with conscious vision at all, but directly to the hypothalamus.

The seat of time perception..
So, blue light synchronizes the hypothalamic clock

Yellow lenses filter out blue light and make the world Sharp, sunny and shiny! 

Yellow glasses are much nicer to wear.
I don't wear them.

Yellow light is brighter; the colour sensitive cones in the fovea (the yellow dot on the back of the retina where colour is perceived) favor yellow light.

One web site told me that:

Only 3-4% of receptors in the fovea are sensitive to blue light, so blue detail is more difficult to perceive.

I don't like blue lenses, but I have two pairs of blue glasses?!

Blue fire is the flame of the spirits...
Blue flame results when sulphur burns
Volcanic...dragon mountain KUR flame!



Quotes from James Hillman:

...blue still brings a principle of darkness with it...

As a hue it is powerful, but it is on the negative side, and in its highest purity is, as it were, a stimulating negation... a kind of contradiction between excitement and repose. As the upper sky and mountains appear blue, so a blue surface seems to recede from us....it draws us after it.

Blue gives us an impression of cold, and thus, again, reminds us of shade. We have before spoken of its affinity with black. Rooms which are hung with pure blue, appear in some degree larger, but at the same time empty and cold.

...objects seen through a blue glass [are] gloomy and melancholy.

More Sulphur!