Colour

toc = = =**Colour**= = =



=**Definition of Color**= "The quality of an object or substance with respect to light reflected by the object, usually determined visually by measurement of hue, saturation, and brightness of the reflected light; saturation or chroma; hue. " (Dictionary.com)

**How We Receive Colour**
At the back of every eye lies the retina which contains to important light sensitive cells known as rods and cones. The rods are greater in number then the cones; 120 million in comparison to the cone’s 6 million. The cones are concentrated in the center of the retina (near the fovea) while the rods are mainly on the periphery. Though the rod’s are more sensitive to light, it is the cone’s that are the cells that receive and decode colour information (Beyon et al. 124).

Our perception is based on the characteristics of light waves. We can only perceive light waves within the visible wave spectrum which includes wavelengths between 400 - 700 nm. The frequency of the light wave is perceived as the hue or colour. The amplitude of the light wave is perceived as saturation.

Colour Blindness
Colour blindness can be defined as individuals who suffer from defective colour vision. The most common form of colour blindness is the Red-Green colour blindness. Men are normally more inclined to become affected with colour blindness due to the fact that colour blindness is a genetic disorder linked to genes in the DNA (1 out of 12 males are affected and 1 out of 25 females are affected). Another form of colour blindness is the Blue-Yellow colour blindness which is more rare than the Red-Green colour blindness disorder, and the rarest form of colour blindness is the Monochromatic Vision disorder in which the individual has no colour detection what so ever (Beyon et al. 124).

**A Piece of History**
During the 1600’s, Sir Isaac Newton began to experiment with a glass prism which lead to his discovery of white light emitted from the sun was in fact made up of different colours. He recognized a distinction between //physical// phenomena and //perceptual// phenomena (Blake 2006, pp 236). Without the factor of light, colour cannot exist because objects themselves do not actually have colour of their own. Colour is a //psychological// phenomenan, entirely subjective. Though objects do not have any colour of their own, objects do have properties that allow them to absorb and reflect different wave lengths of light. Thus we can see red when long frequencies of light waves bounce off an object and on the opposite side of the spectrum, we can see violent when short frequencies of light waves bounce off an object (Bowers 53). In order to see the light waves, our eyes must be equipped with the proper photoreceptors combined in a particular way with the visual neurons in the retina and the brain (Blake 236). The idea of colour has been summed up by Semir Zeki (1983):

//The nervous system, rather than anlayze colours, takes what information there is in the externam environment, namely, the reflectance of different surfaces for different wavelengths of lifht, and transforms that information to construct colours, using its own algorithms to do so. In other words, it constructs something which is a property of the brain, not the world outside. (pp 764)//



(Sir Isaac Newton)

**Additive Colour**
Additive colour is perceived directly as light, such as the colours displayed on a television scree. The primaries of additive colour are red-orange, green and blue-violet. According to Bower, “When these primaries are positioned or added in equal amounts, white light – the source of all colour – is created”, (54).

**Subtractive Colour**
Subtractive colour is perceived as a reflection off of a surface of an object as opposed to additive colour where colour is perceived directly as light. The primaries of subtractive colour are red, yellow and blue. According to Bower, “In subtractive colour, all light waves except those containing the colour we see are absorbed or subtracted by a surface”, (54).

**Complimentary Colours**
These are colours that are located on opposite sides from the colour wheel such as violet and yellow, red and green and what have you. Placing both colour amongst one another creates a complementary contrast and bring a bold feeling to both colours. By mixing and two complementary colours with one another, the effect created by both is a grey (Bowers 57).

**Analogous and Discordant Colours**
Analogous colours are adjacent to one another in the colour wheel (literally beside one another) while the discordant colours are quite far apart from one another in the colour wheel but not directly across from one another like complementary colours. Analogous colours can create a natural harmony with one another such as colours blue and green (nature) while according to Bowers, discordant colours can create a feeling of movement (Bowers 57).

Colour Context
Colour theory can get a little more complicated when viewed in relation to other colours, shapes, and sizes. A red square appears more vivid and brilliant on a black background as opposed to a white background. When placed on an orange background, the red square seems lifeless than when placed on the blue-green background. The same colour can often present different readings depending on how it is displayed. The relationship between one colour paired with another can therefore result in different perceptions.

//image from// [|//www.colormatters.com//]

Color and User Experience
Colour becomes an important role when it is used in design and information visualization. The relationship between colour and the emotions that it evokes should be presented according to the way it relates to the information shown. The usage of colour becomes important in achieving certain perceptions. For example, using different values of the colour blue can suggest an airy and open atmosphere whereas the vividness of red can create an energetic and vibrant sensation. Colour can be used to effect the way something is perceived as well as making the information pleasing to the eye.

Referring back to colour-blindness, it is important to keep in mind that not all users are able to perceive colors the same. This is critical especially in creating optimal user experiences, as a poor choice of color can lead to a loss of end-users. This can easily be prevented by keying into shade; most normal people key into hue. In most colorblindness, the person has a different mixture of cones from normal. The cone cells on the retina are the crucial physical components in seeing color. People with normal color perception have three different cones, each cone is tuned to perceive mostly either Long wavelengths (reddish), Middle wavelengths (greenish), or Short wavelengths (bluish), referred to as L-, M-, and S- cones. Our minds determine what "color" we are seeing by determining the ratio between signals from different types of cones. In people with colorblindness, either a type of cone is missing, or the cone has a different peak absorption from normal

To see how people with color-blindness perceive colors, visit http://www.iamcal.com/toys/colors/ Colorblindness is caused by the different mixture of cones from normal. The cone cells on the retina are the crucial physical components in seeing color. People with normal color perception have three different cones, each cone is tuned to perceive mostly either Long wavelengths (reddish), Middle wavelengths (greenish), or Short wavelengths (bluish). Our minds determine what "color" we are seeing by determining the ratio between signals from different types of cones. In people with colorblindness, either a type of cone is missing, or the cone has a different peak absorption from normal (webexhibits).

Color Symbolism: The Use of Color for Meaning
It should be stated off-hand that the symbolism being color varies from culture to culture. For instance, in America, black is associated with death and white with purity and life. However in Asia, white is the traditional color for mourning. According to the creative behavior website, the general symbology for the basic colors in Western culture is as follows:

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 * Red: urgency, passion, heat, love, blood, excitement, strength, sex, passion, speed, danger
 * Yellow: warmth, sunshine, cheer, happiness, cowardice, brightness
 * Blue: truth, dignity, power, coolness, melancholy, heaviness, trust, reliability, belonging, coolness
 * Orange: playfulness, warmth, vibrant
 * Green: nature, health, cheerfulness, environment, money, vegetation, nature, fresh, cool, growth, abundance
 * Purple: wealth, royalty, sophistication, intelligence, royal, spirituality, dignity
 * Pink: soft, sweet, nurture, security
 * Black: sophistication, elegant, seductive, mystery, death, rebellion, strength, evil
 * White: purity, cleanliness, lightness, emptiness, pure, virginal, clean, youthful, mild

At the end of the day, meaning of color is subjective to every individual. Some people react differently to particular colors on an emotional, physical and spiritual level. Therefore color is a crucial consideration for artists and designers, as each hue draws a certain reactive response from the user.

"Applying color principles fosters desired audience response. Warm colors tend to "move toward you" while cool colors tend to "move away from you." So a designer can use warm colors for emphasis and cool colors to minimize emphasis. Brighter colors attract our eyes first, and if overused, can cause visual confusion. " (Yost)

For more information on color symbolism, please check out this fun and interactive flash website by Maria Claudia Cortes:


 * [|http://www.mariaclaudiacortes.com/colors/Colors.swf]**


 * References**

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 * Benyon, David, Turner, Phil, and Susan Turner. //Designing Interactive Systems: People, Activities, Contexts, Technologies.//
 * Bowers, John. //Introduction to Two-Dimensional Design: Understanding Form and Function.// New York: John Wiley & Sons, 1999.
 * Colour Context 
 * Colour Table //://]>
 * Colour Wheel 
 * Yost, Maura. "Emotions of Color". //CreativeBehavior.// 2006. <[|http://www.creativebehavior.com/index.php?PID=42]>
 * Blake,, Randolph and Robert Sekuler. //Perceeption: Fifth Edition//. Boston: Allyn, 2000.
 * Professor Littlejohn's Week 5 Lecture Notes, Slide 13 & 16
 * "Color Blindess" 