Color theory is a group of basic rules in the mixing of color perception to achieve the desired effect by combining colors of light or combining colors reflected in pigments.
In the practical field of the use of color, the knowledge we have and have acquired about it refers to pigment color and comes from the teachings of the old French Academy of Painting, which considered primary colors (those that by mixing will produce all other colors ) to red, yellow and blue.
Based on this practical knowledge, we see that there are actually two primary color systems: light primary colors and pigment primary colors.
Summary
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- 1 Subtractive color mixing
- 2 Color
- 1 What is light?
- 2 What are pigments?
- 3 What is absolute reflection and absorption?
- 3 Color properties
- 1 Hue (Hue)
- 2 Saturation or Intensity
- 3 Brightness
- 4 Brightness
- 4 Sources
Subtractive color mixing
The colors (pigments) that absorb light from the primary additive colors ( red , blue and green : light colors ) are called primary subtractive colors. They are magenta (which absorbs green ), yellow (which absorbs blue ) and cyan ( greenish blue , which absorbs red ).
So, if pigments are mixed, it is a subtractive mixture since with each pigment that is added, what we do is absorb more parts of the spectrum; that is, more primary colors, and the end result will be the absence of light : black .
Thus, magenta , cyan and yellow are pigment colors, their fusion gives black . They are the colors used in printing, inks and paper . Their mixture is called subtractive synthesis and it is common in all printing systems, paints, dyes and colorants.
So, when talking about color mixing, we must differentiate between additive mixing and subtractive mixing. If lights are mixed it is an additive mixture and the result of the total combination is white light. You can reproduce any sensation of color by mixing different amounts of red, green and blue lights. This is why these colors are known as additive primaries.
In the case of pigments used in paints, markers, etc., yellow, magenta and cyan are used as basic colors for mixing.
Colour
The Color is a visual impression that the subject of the object. Consequently, it is the result of a multiple process involving different elements, factors and processes (physical, biological and neuro-psychological).
The different sensations of color correspond to light that vibrates with different frequencies, ranging from approximately 4 × 1014 vibrations per second in red light to approximately 7.5 × 1014 vibrations per second in violet light ”
Starting from white light, its perception through sight and the associative relationship that the brain makes based on what is perceived, the phenomenon develops consecutively, as long as we are able to perceive the reflection of light in matter . Let’s look at this broad definition of the phenomenon:
Color, physical phenomenon of light or vision, associated with different wavelengths in the visible area of the electromagnetic spectrum . As a sensation experienced by humans and certain animals, the perception of color is a very complex neurophysiological process. The methods currently used for color specification fall within the specialty called colorimetry, and consist of precise scientific measurements based on the wavelengths of three primary colors.
Understanding the above, a circumscribed definition of two elements is necessary: light and matter (pigments).
What is light
We can well understand light as a “form of electromagnetic radiation similar to radiant heat, radio waves or X-rays ”
The light corresponding to oscillations extremely fast of an electromagnetic field in a given frequency range can be detected by the human eye. The light spectrum can be seen when a beam of white light passes through a glass or prism and as a result of refraction it decomposes and spreads throughout its range. In particular, the three colors 1/3 or basic colors of light stand out (they are so called since they occupy 1/3 of the light spectrum and the remaining 2/3, as a result of the interaction between the 1/3 colors.
“Visible light is made up of electromagnetic vibrations whose wavelengths range from about 350 to about 750 nanometers (billionths of a meter). White light is the sum of all these vibrations when their intensities are approximately equal. In all light radiation two aspects can be distinguished: one quantitative, its intensity, and the other qualitative, its chromaticity ”
The properties of light have always troubled man. In the middle of the seventeenth century is where we find the first treatises and theories about its conformation and properties. From Isaac Newton ( 1642 – 1727 ) to Einstein ( 1879 – 1955 ), in order to explain the photoelectric effect, many theories were formulated; the latter suggested “that light, as well as other forms of electromagnetic radiation, travels in small beams of energy called light quanta or photons.” Hence, light has a double quality: wave-particle. Its frequency and length give it wave characteristics, but its mass and quantum conformation mark behavior as a particle or photon .
“Light is emitted from its sources in a straight line, and diffuses over an ever larger surface as it progresses; light per unit area decreases as the square of the distance. ”
Otherwise, we can also say that visible light (white light) is made up of electromagnetic emissions that travel through space in the form of waves, ordered to a lesser or greater degree, according to their wavelength (expressed in nanometers) and its frequency. And since light is equal to energy, we can define its concept as follows:
“It is the energy that is transmitted in the form of waves through space, of which the light spectrum forms part. All electromagnetic energy is the same throughout the spectrum, differing only in its wavelength and frequency.”
Across the broad spectrum of electromagnetic energy, we can find very long waves (reaching up to 1 km in length corresponding to electrical energy) or very short (gamma and alpha rays, well below the unit nanometer). Of course, all these emissions are invisible to man. As for the light spectrum, we know that it is part of the electromagnetic spectrum, defined by a certain range of length and frequency. It is defined as follows:
“… in the visible spectrum it is the small fraction of the electromagnetic energy to which the eyes of the human being are sensitive and it covers a range of length that goes from 400 to 700 nanometers (billionth of a meter; the nanometer is a new term of the metric system, accepted as a world “standard”, with the exception of Burma, Liberia and the United States … ”
What are pigments?
The ability of objects to reflect a certain emission of light waves is due to the physical composition of their exterior. In this case we are talking about the pigments that make up these objects or things. Pigments are present in almost all matter. And they are defined as follows:
“A colored substance that is insoluble in the medium where it is spread. A pigment is distinguished from an ink or a dye because the latter are soluble in the mediums or vehicles with which they are mixed. They are usually classified or categorized according to their origin, whether organic (animal, vegetable or synthetic organic) or inorganic (mineral or synthetic inorganic) ”
Pigments were made at first, from plants and minerals, which were processed, grinding and pulverizing the matter that made it up to later bind it in a certain medium and manipulate it on other objects or things. The binder is the medium where the pigment is carried, an example of this is oil, made up of one or more pigments and an oil-based binder.
In their molecular conformation, these materials have certain characteristics that determine their physical reaction to light, reflecting a fraction of it and absorbing the remaining energy that is incident, giving us the chromatic impression that corresponds to the pigment placed on the given matter.
“All objects have the property of absorbing and reflecting certain electromagnetic radiation. (…) Almost all objects owe their color to filters, pigments or paints, which absorb certain wavelengths of white light and reflect or transmit the others; these reflected or transmitted wavelengths are what produce the sensation of color, which is known as pigment color. ”
What is absolute absorption and reflection?
The light white “comprises electromagnetic, waves different from each other by their lengths”, ie, a beam of white light traveling electromagnetic waves all wavelengths corresponding to each color, all at once. Thus, we have that white light contains, in short, the entire range of electromagnetic emissions that the human eye can perceive. When we decompose this light into all or some of its parts, it is when we can capture one or more colors. This can happen at the moment of reflection or refraction on a matter or through it.
The following basic colors result from the refraction of light: blue – violet (AV), blue – cyan (AC), green (V), yellow (A) and red – orange (RN). The magenta results from the mixing of the ends of the spectrum: violet-blue and red-orange. These five names comprise a generalization of the spectrum, since in practice not all other intermediate colors are usually named.
Now, each matter or element is capable of a certain wavelength (remember the point “pigments”) when exposed to radiation. The element, by reflecting a certain wavelength, is absorbing the rest of the other waves; therefore, what we perceive is the reflection of a color . Unlike this effect, in case of absorbing all the waves and not reflecting anything, it is what we would call absence of color or absolute absorption that corresponds to black. Therefore, black is not a color; it does not reflect light and therefore none of its electromagnetic emissions. Now let’s define the concept:
“It is the absence of light or light reflection (transmission) by a material or element, giving the impression of black (…) No black is absolute. There is a theory about the Blackbody (blackbody), a term used by modern physicists, as the ideal substance that absorbs all the radiation and does not reflect anything on it. But in practice, even the darkest terrestrial material reflects at least 3% of the incident radiation. ”
As it is a complex process of factors, we find some doubts about its physical and chemical mechanics with respect to certain substances:
“The mechanism by which substances absorb light is not well understood. Apparently, the process depends on the molecular structure of the substance. In the case of organic compounds, only unsaturated compounds show color (…) Inorganic compounds are usually colorless in solution or in liquid form, except for the so-called transition elements ”
Color properties
Hue (Hue)
Hue (hue) or hue is the attribute that differentiates the color and by which we designate the colors: green , violet , orange. It is the pure state of color, without the white or black aggregates, and is an attribute associated with the wavelength dominant in the mixture of light waves. The Tint is defined as a color attribute that allows us to distinguish red from blue, and refers to the path that a tone makes towards one or the other side of the chromatic circle, so green yellowish and teal will be different shades of green. The 3 primary colors represent the 3 primary shades, and by mixing these we can obtain the other shades or colors. Two colors are complementary when they face each other on the hue circle (color wheel).
Saturation or Intensity
Saturation is the chromatic intensity or purity of a color. Value is the lightness or darkness of a color , it is determined by the amount of light that a color has. Value and brightness are the same thing.
Also called Chroma, this concept represents the purity or intensity of a particular color, its vividness or paleness, and it can be related to the bandwidth of the light that we are visualizing. The pure colors of the spectrum are completely saturated. An intense colour is very alive. The more a color is saturated, the greater the impression that the object is moving.
It can also be defined by the amount of gray that a color contains: the grayer or more neutral it is, the less bright or “saturated” it is. Likewise, any change made to a pure color automatically lowers its saturation.
For example, we say “very saturated red” when we mean pure, rich red. But when we refer to the shades of a color that has some gray value, we call them less saturated. Color saturation is said to be lower when its opposite (called complementary) is added to the color wheel.
To desaturate a color without changing its value, it must be mixed with a black and white gray of the same value. A rich color such as blue will lose its saturation as white is added and it becomes light blue.
Another way to desaturate a color is to mix it with its complement, since it causes its neutralization. Based on these concepts we can define a neutral color as one in which its saturation is not clearly perceived. The intensity of a color is determined by its light or off character.
This property is always comparative, since we relate intensity compared to other things. The important thing is to learn to distinguish intensity relationships, since intensity often changes when one color is surrounded by another.
Brightness
Amount of light emitted by a light source or reflected by a surface.
It is a term used to describe how light or dark a color appears , and refers to the amount of light perceived. Brightness can be defined as the amount of “darkness” that a color has, that is, it represents how light or dark a color is in relation to its standard color.
It is an important property, since it will create spatial sensations through color. Thus, portions of the same color with strong differences in value (value contrast) define different portions in space, while a gradual change in the value of a color (gradation) gives a sense of contour, of continuity of an object in space.
The value is the highest degree of lightness or darkness of a color. A blue , for example, mixed with white , results in a lighter blue, that is, of a higher value. Also called tone, it is different from color, since it is obtained by adding white or black to a base color.
As more black is added to a color, the darkness intensifies and a lower value is obtained. As more white is added to a color, its clarity intensifies, resulting in higher values. Two different colors (such as red and blue) can have the same tone, if we consider the concept as the same degree of lightness or darkness in relation to the same amount of white or black they contain, depending on each case.
The classic description of the values corresponds to light (when it contains amounts of white), medium (when it contains amounts of gray) and dark (when it contains amounts of black). The brighter the color, the greater the impression that the object is closer than it actually is.
Brightness
Amount of light reflected by a surface compared to that reflected by a white surface under the same lighting conditions.
These properties of the color have given rise to a special system of representation of these, as we have seen in the previous section, HSV system. To express a color in this system, we start from the pure colors, and their variations in these three properties are expressed by a percentage. We can use these properties in the search for the appropriate color ranges and contrasts for our pages, being possible to create contrasts in hue, saturation and brightness, and the latter is perhaps the most effective.
