Colours in the dark

I am intrigued by colour. Especially when it is in an unusual surrounding, like photography with polarisers and filters. It sometimes results in a very dark, almost black background, giving an eerie feeling to the scene. Especially when the colours in the foreground is a vivid green or red. 
One can see that it is not done at night, because of the brightness of the colour. No black and whiting or greys as one sees at night without a light. Sometimes one can get a similar effect at night when using a flash if the background is far enough distant not to be lit by the flash. 
Usually it does not have the same effect. Polarisers work well to darken the sky, giving a "night at daytime" effect like you get naturally when a big storm is brewing or the eerie light that comes with a partial solar eclipse. 
It is really amazing that the colour that one perceives can set the mood for a scene. Especially if one keeps in mind that colour is actually just different frequencies of light, which in turn is actually just a very small selection of frequencies of electro-magnetic radiation . 
One can not be sure that everybody perceives light in the same way. This is done by the brain, which interprets the nerve impulses from the eyes. The only way we can "calibrate" colour perception between different people, is by shining a "white" light through a prism, separating it into the colours of the rainbow and using each separate colour as a reference point of basic colour. Not all people even have the ability to "see" colour. Some are colour blind and either see in shades of grey, or perceives different colours as the same one. This can vary in severity from person to person and is more prevalent in males than in females. 
This can allow us to have an idea how different people "see" colour, but still does not give us insight into how every individual feels about colour or what mood certain shades invoke in people. This is, I think, a very special and individual experience. It is like certain smells that stir the memory and bring back the happenings of days gone by. To every one it is as different as their individual history, culture and memory. 
Eventually it is what you feel inside yourself when you see it that makes colours and shades special. It is the connotation your brain assigns to it, not the frequency of the radiation itself... 
Come to think of it, to a certain extent, the combination of colours and the contrast between the different colours may be even more important than one colour on its own. 
Perhaps Don McLean captured in words what Van Gogh captured in paint on canvas with his song: 

"VINCENT"


"Starry, starry night.
Paint your palette blue and grey,
Look out on a summer's day,
With eyes that know the darkness in my soul.
Shadows on the hills,
Sketch the trees and the daffodils,
Catch the breeze and the winter chills,
In colours on the snowy linen land.
Now I understand what you tried to say to me
how you suffered for your sanity
how you tried to set them free.
They would not listen
they did not know how
perhaps they'll listen now. 
Flaming flowers that brightly blaze, Swirling clouds in violet haze,
Reflect in Vincent's eyes of china blue.
Colours changing hue, morning field of amber grain,
Weathered faces lined in pain,
Are soothed beneath the artist's loving hand.
For they could not love you,
But still your love was true.
And when no hope was left in sight
On that starry, starry night,
You took your life, as lovers often do.
But I could have told you, Vincent,
This world was never meant for one
As beautiful as you.
Portraits hung in empty halls,
Frameless head on nameless walls,
With eyes that watch the world and can't forget.
Like the strangers that you've met,
The ragged men in the ragged clothes,
The silver thorn of bloody rose,
Lie crushed and broken on the virgin snow.
Now I think I know what you tried to say to me,
How you suffered for your sanity,
How you tried to set them free.
They would not listen, they're not listening still.
Perhaps they never will... "