Notions about color

Color, like lines and texture, is a visual property possessed by all shapes and spaces, making it a very necessary element in the universal aesthetic language.

Interior decorators use color daily to provide functionality and aesthetics to rooms, so they must be familiar not only with cultural issues (such as fashion and traditions) in the use of color, but also with practical issues such as: its usefulness, influence on the mood of humans and the ways to obtain them by combining different pigments.

Physics of color

As we can see, when a ray of white light passes through a prism, light scattering occurs, this is because the white light wave is composed of several wavelengths, which upon entering a different medium (the prism glass) experience different speeds, making visible the colors that make up white light: red, orange, yellow, green, blue and violet.

What happens when a beam of white light strikes an opaque surface is the selective absorption of certain wavelengths of light, reflecting others. For example: a red surface absorbs most of the white light waves and reflects only the red ones. Likewise, a surface of any other color reflects only the waves corresponding to that color; a white surface reflects the entire spectrum and a black surface absorbs the entire spectrum.

All objects when illuminated absorb a part of the electromagnetic waves (colors) contained in the light and reflect the remaining ones. The color of objects is the color of the light reflected from them as it is captured by our eyes and processed by our brain. The eye can capture colors only when there is abundant illumination, however when there is little light, it can only capture black and white objects.

Primary colors

For several centuries men in their eagerness to obtain new colors have experimented with different mixtures until they empirically determined that by combining a reduced number of colors (primary colors) all the other existing colors can be obtained.

With the advances in the studies of the physics of light and the biology of its perception, it has been determined that the primary colors depend on the source of the color, which can be:

• A light source that emits light with a particular color.
• An object that absorbs a part of the light it receives and reflects another part that we interpret as the color of the object.

Taking into account the two sources of color we can distinguish three main models of its obtaining or synthesis:

• The traditional synthesis.
• The additive synthesis.
• The subtractive synthesis.

The traditional synthesis is based on the practical knowledge on the handling of pigments, considering that from the mixture of the primary colors (blue, red and yellow) the rest of the colors can be obtained.

In reality, the mixtures of these primary colors do not offer the possibility of obtaining all the rest of the colors, especially purple and green. Page break The additive synthesis is based on the fact that the colored lights that are superimposed, are added forming lighter tones. The primary light colors are red, green and blue; by combining one of these primary colors with another in equal proportions, the secondary colors cyan, magenta and yellow are obtained. White is obtained by adding the three primary colors, and black is obtained by the absence of the three primary colors.

Additive synthesis is used to achieve the different colors on the screen of the cinema, TV, computer, cell phone, etc.

Subtractive synthesis is based on mixing pigments and dyes to make the object reflect certain colors (parts of the electromagnetic spectrum) and absorb others.

The primary colors are yellow, magenta and cyan, each acting as a filter, yellow does not allow the waves that form blue to pass through, magenta does not allow green waves to pass through and cyan does not allow red waves to pass through. The secondary colors are blue, green and red. The mixture of the three primary colors should theoretically produce black, although in practice black pigment is added to enhance the color. Subtractive synthesis is used to achieve the different colors in photography and painting.

Pigments and dyes

Pigments and dyes are substances capable of changing the colors of light reflected from opaque surfaces because they selectively absorb certain light waves and reflect others, forming a new spectrum of light that gives the appearance of the new color.

The appearance of color is closely related to the properties of the light they receive. The color we perceive when a surface is illuminated by sunlight (which has a relatively uniform spectrum), will not be exactly the same as the color we receive when the same surface is illuminated by artificial lights that have large variations in some parts of their spectrum.

This principle should be considered by the decorator when selecting the colors of the paints to be used, since it is possible that a paint applied outdoors seems suitable for a room and after painting it, the results are not as expected, because the light resources used or the coatings of the room are different. For that reason it is recommended to test the paints in the places where they will be applied.