Friday, 11 January 2013

SYSTEMATIC COLOUR: INTRODUCTION TO COLOUR PRINCIPLES, PART 1/2

- Systematic investigations, and subjective outcomes.
- Colour is about personal perception of colour, therefore a systematic approach in view of colour is necessary for standardisation.

Colour is important in regards of readability and legibility of type:
- Black/white, white/black.
- Colour can hinder readability and legibility, for example, pale text, or green text on red background. I have created the example below to show how readability and legibility can be affected due to colour:



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How does the eye perceive colour?

"The human eye and brain together translate light into color. Light receptors within the eye transmit messages to the brain, which produces the familiar sensations of colour.






Newton observed that color is not inherent in objects. Rather, the surface of an object reflects some colors and absorbs all the others. We perceive only the reflected colors.
Thus, red is not "in" an apple. The surface of the apple is reflecting the wavelengths we see as red and absorbing all the rest. An object appears white when it reflects all wavelengths and black when it absorbs them all.

Red, green and blue are the additive primary colors of the color spectrum. Combining balanced amounts of red, green and blue lights also produces pure white. By varying the amount of red, green and blue light, all of the colors in the visible spectrum can be produced.
Considered to be part of the brain itself, the retina is covered by millions of light-sensitive cells, some shaped like rods and some like cones. These receptors process the light into nerve impulses and pass them along to the cortex of the brain via the optic nerve.


Rods and Cones:



Rods are most highly concentrated around the edge of the retina.

There are over 120 million of them in each eye. Rods transmit mostly black and white information to the brain. As rods are more sensitive to dim light than cones, you lose most color vision in dusky light and your peripheral vision is less colorful.

It is the rods that help your eyes adjust when you enter a darkened room.

Cones are concentrated in the middle of the retina, with fewer on the periphery. Six million cones in each eye transmit the higher levels of light intensity that create the sensation of color and visual sharpness.

There are three types of cone-shaped cells, each sensitive to the long, medium or short wavelengths of light. These cells, working in combination with connecting nerve cells, give the brain enough information to interpret and name colours.

The human eye can perceive more variations in warmer colors than cooler ones. This is because almost 2/3 of the cones process the longer light wavelengths (reds, oranges and yellows).

1st; reds, orange yellow
2; green
3; blue-violet

About 8% of men and 1% of women have some form of color impairment.

Most people with color deficiencies aren't aware that the colors they perceive as identical appear different to other people. Most still perceive color, but certain colors are transmitted to the brain differently.

The most common impairment is red and green dichromatism, which causes red, and green to appear indistinguishable. Other impairments affect other color pairs. People with total color blindness are very rare.

Interesting facts on the perception of colour:

Birds, fish and many other mammals perceive the full spectrum. Some insects, especially bees, can see ultraviolet colors invisible to the human eye.

In fact, color camouflage, one of nature's favorite survival mechanisms, depends on the ability of the predator to distinguish colors.

Until recently, it was thought that dogs didn't see any color at all. Recent studies now show, however, that dogs can differentiate between red and blue and can even pick out subtle differences in shades of blue and violet."

Source: pantone


- Wavelengths:

We see a small part of the visible spectrum ranging from 390 to 750 nm (nanometers, one billionth of a metre) wavelength. Within this tiny part of the spectrum are all the colours of light available to human perception, differentiated by further subdivision of wavelengths of electromagnetic radiation as illustrated here:


Daylight contains all the wavelengths of visible light and appears to the human eye to be white. However, as demonstrated by a prism (that separates light according to its wavelength) white light actually comprises of the entire visible spectrum. Furthermore light can be absorbed or reflected according to the wavelength, hence different surfaces or materials appear to be coloured. The mechanism by which the human eye perceives colour is shown in below:
 Source: potsofpaint


Colour doesn't exist until mixed into pigments/ink, for example paper or textiles.

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Primary, Secondary and Tertiary Colours:

Primary
Secondary
Tertiary

Source: tigercolor.com

Primary: Primary colours cannot be made by mixing any other colours together; Red, Blue and Yellow.
Secondary: The result of mixing two primary colours together; Green, Purple and Orange.
- Red and Yellow = Orange
- Blue and Red = Purple
- Blue and Yellow = Green
Tertiary: Browns and Greys containing all three primary colours together, or by mixing a primary and secondary colour together.


Source: infographiclist

Complimentary: Colours opposite one another in the chromatic colour circle are complimentary colours, for example, green and purple.
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Colour Modes:

RGB (Red, Green, Blue; On-Screen/Optical/Digital colour mode):

"In the RGB system, the red, green and blue dots are assigned brightness values along some scale, for example 0 to 255, where 0 is dark and 255 is bright. By listing the three values for the red, green and blue phosphors, you can specify the exact color that will be mixed.



Additive colors get lighter when mixed. As each component of light is mixed in, the combination becomes a new color.


Red, green and blue are the three additive primaries. You can mix any color of light with different combinations of the additive primaries. When you mix all three together in balanced amounts, you get white.

These three primaries are the basis of the additive color model. 

ADDITIVE COLOUR

CMYK (Cyan, Magenta, Yellow, Black) Model:
Cyan, magenta and yellow are the three subtractive primaries. Nearly any color can be produced with different combinations of these three colors. When you mix all three together in equal amounts, you get a near black.
These three primaries are the basis of the subtractive color model. That's why it's called the CMY model. A close relative of the CMY model, called CMYK, is commonly used by printers and some software.
In theory, you can mix any reflective color by mixing a combination of cyan, magenta and yellow.

Subtractive colours get darker when mixed. Each of the mixed paints or inks absorbs different components of the light. If the right combination of paints is mixed together, all of the components of light are absorbed and the result is a near black."
Source: pantone

SUBTRACTIVE COLOUR





Source: crasstalk

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Chromatic Value: Hue + Tone + Saturation. The chroma or chromatic value indicates how pure the colour is.
Hues: Different hues/variations of a colour the spectrum, for example, purple/green, dark/light, considering saturation and tone. Different hues are caused by different wave lengths of light.
Hue is affected by Saturating/de-saturating colour by adding colour. Eventually the colours will be cancelled out as shown below:



Shows highest chromatic value, and desaturation of colours. Tertiary colours created by mixing or crossing complimentary colours. The end result is a highly chromatic colour.

Saturation: Related to chromatic value, saturation tells us how a color looks under certain lighting conditions. For instance, a room painted a solid color will appear different at night than in daylight. Over the course of the day, although the color is the same, the saturation changes. This property of color can also be called intensity. Pure and Strong colour.

  

Tertiary Colour wheel; no colour.



Chromatic Value affected by Saturation.


Hue, Saturation and Value shown here with high/low values, and different saturations. Both are relative to the hue selected. Shades are created by adding black, whilst tints are created by adding white.



As perception is different from person to person, a subjective approach to identifying colours is vital for continuity and structure. 

Source: tigercolor.com

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Pantone Colour Matching System was created to standardise colour using tints, shades and hues, showing the make up of each individual colour:

- Pantone is an 'agreed set of colours'
- Colour swatches are globally recognised
- Recognised by printers, designers and institutions.

Coated: Shiny stock
Uncoated: Matte
Ink is printed differently for the 2 types of stock.

The code shows the chromatic value. Working with colour has to be systematic.



Source: pantone


This video shows the making of pantone colour.

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During the session the class as whole created a colour wheel made up of over 200 objects and colours. In groups, we were then asked to match the colour of several objects of a particular hue, with different shades and tints.

Below you can see the results:







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Pantone colour matching blue objects of our colour wheel:






 Photos via k-shaw1215-dp (team member during the session)

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