We all have a favorite and others that we dislike. It has been proven that colors represent a state of mind, and that for each culture they mean something different. They even popularly designate the hierarchical order of the Power Rangers. Although we all use them, it is worth asking what is color?
Before coloring, first let’s light up. Electromagnetic radiation is the transport of energy by means of two oscillating fields, electric and magnetic, that propagate through space. – – The portion that the human can see of the radiation we call light, which is a wave-particle that spreads spherically. Thanks to the photoelectric effect, which Einstein himself deduced, we now know that light is composed of mass-less particles, called photons, that travel in the form of waves.
Thus we come to the famous electromagnetic spectrum, which brings together the various levels of radiation. From left to right, the order is decreasing in terms of energy and frequency, but at the same time it is increasing for the wavelength; that is, the higher the frequency, the greater the number of photons transported-greater energy-but the smaller the length. Of all that spectrum, only a small part is visible to the human being, which is why we appropriately call it “visible spectrum”.
Two «types» of colors
The visible spectrum is only white light and its behaviors: refraction, propagation, diffraction, interference, reflection, dispersion and polarization.
Newton, just experimented with a beam of light, upon discovering that it breaks down into the seven colors of the rainbow -violet, blue, cyan, green, yellow, orange and red-, and by combining them he obtained white light.
It must be mentioned that all this is possible because of the type of star that is the Sun, because if it were a blue giant, our visible spectrum would be further to the left – ultraviolet vision!
Now, one thing is the proper color of light and another is its relation to matter. The so-called “light colors” are born from the objects that emit light: the stars, the fluorescent compounds, the bio luminescent living beings or the electronic devices, so the color is not tangible. On the other hand, “pigment colors” are the physical manifestation of color, characteristic of matter, which they can paint or dye, like inks or natural and artificial dyes. The physical process of the pigments depends on the partial absorption and reflection of the radiation; that is, a carrot is orange because its natural pigment – carotene – does not absorb the “orange light”, but reflects it and thus our eyes perceive it as orange.
Jane Austen says …
The culprits of our perception of color are the cones and canes contained in the eyes. These two cells share the chamba to identify the absorption or not of the light -color- and its intensity. They are named for the shape of their outer segments, where one is confided and the other straight – although it does not have the curvature of a walking stick.
On the one hand, the canes are photo receptor cells that are extremely sensitive to light, which is why they are responsible for vision when there is low luminosity – non-urn vision. The work of the sticks only has to do with the intensity of the light, therefore, they are unable to detect the color. These cells are located in the retina, except in the forgave – in the back of the eyeball – and contain a natural pigment called Rhodesian.
Then, the cones are another type of cells less photosensitive than the rods, which are located in the retina -especially in the fovea-, and these are the ones that make us perceive the color. In addition, primates have the privilege of having three types of cones, which distinguish up to three colors of light: type S, which perceive light in the blue spectrum and contain cyanotopsin; the M, for the green light, with chloroplast; and the L, for the red spectrum, thanks to erythromycin.
The secret of Victoria
However, life is not rosy, because standardizing all these concepts is something more complicated – and that without getting into the discussion of whether two people really perceive the same color equally. Fortunately, we are already familiar with the concepts of primary, secondary and tertiary colors. From the primaries, all the others arise, because there are two ways of obtaining colors.
One is the additive synthesis of light colors, which was explained by the English polymath Thomas Young: “any color is obtained by the addition or addition of others, and the end result is always the target.” The models that are based on this synthesis are the CIE, RGB, HSV / HSL and the composite video -lime and dominance-. The HSV / HSL models are structured by the properties of the color, while the RGB models are based on the control of the intensity of the primary colors: red, green and blue -which acronyms in English give name to this model: red, green and blue-, from which the secondary magenta, yellow and cyan are born. And, oh, surprise !, every electronic device that boasts of having a screen, uses this model, as well as our own perception of color.