Colour Lectures 1, 2, 3 & 4

Lecture 1

Even though most words in this paragraph are spelt wrong, it is still easily legible and easy to read. The brain when reading a word reads to first and last letter an from memory puts one and one together despite the spelling mistake.

The eye contains to kinds of receptors- rods and cones

While the rods convey shapes of gray, the cones allow the brain to perceive colours.

Of the three types of cones, the first is sensitive to red-orange light, the second to green light and the third to blue-violet light.

When a single cone is stimulated, the brain perceives the corresponding colour.

•If our green cones are stimulated, we see "green".

•If our red-orange cones are stimulated, we see "red".

•If both our green and red-orange cones are simultaneously stimulated, our perception is yellow. 

Primary Colours Differs in each mode (RGB/CMYK). Colours that are seen when sunlight is shone through a prism are called the spectrum colours. These colours are;

RED,ORANGE,YELLOW,GREEN,BLUE,INDIGO,VIOLET. 

 Primary colours base of the RGB/additive colour system. These ROYGBIV colours  are reduced to red, green, blue-violet. 

Secondary ColoursThese colours are simply created from mixing 2 primary colours. 

Red and yellow produce orange. 

Yellow and blue produce green. 

 & Red and blue to produce violet. 

  RGB

 RGB & CMYK

•The eye cannot differentiate between spectral yellow, and some combination of red and green.

•The same effect accounts for our perception of cyan, magenta, and the other in-between spectral colours. 

Subtractive colour and Addictive colour.

'...A subtractive color model explains the mixing of paints, dyes, inks, and natural colorants to create a full range of colors, each caused by subtracting (that is, absorbing) some wavelengths of light and reflecting the others. The color that a surface displays depends on which colors of the electromagnetic spectrum are reflected by it and therefore made visible. Subtractive color systems start with light, presumably white light. Colored inks, paints, or filters between the viewer and the light source or reflective surface subtract wavelengths from the light, giving it color. If the incident light is other than white, our visual mechanisms are able to compensate well, but not perfectly, often giving a flawed impression of the "true" color of the surface. Conversely, additive color systems start without light (black). Light sources of various wavelengths combine to make a color. In either type of system, three primary colors are combined to stimulate humans’trichromatic color vision, sensed by the three types of cone cells in the eye, giving an apparently full range' - http://en.wikipedia.org/wiki/Subtractive_color

'... a Addictive color model involves light emitted directly from a source or illuminant of some sort. The additive reproduction process usually uses red, green and blue light to produce the other colors. Combining one of these additive primary colors with another in equal amounts produces the additive secondary colors cyan, magenta, and yellow. Combining all three primary lights (colors) in equal intensities produces white. Varying the luminosity of each light (color) eventually reveals the full gamut of those three lights (colors). Computer monitors and televisions are the most common form of additive light. The colored pixels do not overlap on the screen, but when viewed from a sufficient distance, the light from the pixels diffuses to overlap on the retina. Another common use of additive light is the projected light used in theatrical lighting, such as plays, concerts, circus shows, and night clubs. Results obtained when mixing additive colors are often counterintuitive for people accustomed to the more everyday subtractive color system of pigments, dyes, inks and other substances which present color to the eye by reflection rather than emission. For example, in subtractive color systems green is a combination of yellow and blue; in additive color, red + green = yellow and no simple combination will yield green. Additive color is a result of the way the eye detects color, and is not a property of light. There is a vast difference between yellow light, with a wavelength of approximately 580 nm, and a mixture of red and green light. However, both stimulate our eyes in a similar manner, so we do not detect that difference...'  - http://en.wikipedia.org/wiki/Additive_color

Tertiary colours

Tertiary colours are browns and grays and they contain all 3 primary colours. 

They are created by mixing either all 3 primary colours together or a primary colour  and secondary colour. '...Tertiary colors are combinations of primary and secondary colours. There are six tertiary colors; red-orange, yellow-orange, yellow-green, blue-green, blue-violet, and red-violet. An easy way to remember these names is to place the primary name before the other colour. So the tertiary colour produced when mixing the primary colour blue with the secondary colour green, is called 'blue-green'....' -http://www.colourtherapyhealing.com/colour/tertiary_colours.php


Lecture 2- Systematic Colour


Dimensions of colour 


Cyronmnic Value =
HUE + TONE =SATURATION 

HUE

HUE

SHADE, TINT & LUMINANCE 

SHADES, TINT,  TONES AND LUMINANCE 

HUE

SATURATION 

SATURATION

SATURATION

'...HSL and HSV are the two most common cylindrical-coordinate representations of points in an RGB color model, which rearrange the geometry of RGB in an attempt to be more intuitive and perceptually relevant than the cartesian (cube) representation. They were developed in the 1970s for computer graphics applications, and are used for color pickers, in color-modification tools in image editing software, and less commonly for image analysis and computer vision...' - http://en.wikipedia.org/wiki/HSL_and_HSV

PANTONE! PANTONE IS YOUR BEST FRIEND 

 If you want to work with colour in design it has to be Systematic. Here is a website whch is all to do with pantone colour http://www.pantone.co.uk/pages/pantone/index.aspx

'...Pantone colours are an agreed, industry standard set of colours that can be matched to accurately over a variety of processes, equipment and materials. They are identified as a series of numbers instead of names (except with fashion colours), so you will hear the reference PANTONE 2985 C instead ofSky Blue. This helps a great deal as one person's idea of what Sky Blue is may be very different to another person, but with a number you can refer to the chart and you know exactly what you are getting. Keeping colours consistent is a big issue with Infiniti Mixed Media and is very difficult to do over different systems like print and the web. A certain amount of colour shift is inevitable, but I work hard to try and keep this to a minimum....' - http://www.infinitimixedmedia.com/faqs/127-what-are-pantone-colours.html

LECTURE 3- Colour & Contrast

The eye contains two kinds of receptors: rods and cones. While the rods convey shades of gray, the cones allow the brain to perceive color hues. Of the three types of cones, the first is sensitive to red-orange light, the second to green light and the third to blue-violet light. When a single cone is stimulated, the brain perceives the corresponding color. That is, if our green cones are stimulated, we see "green". Or if our red-orange cones are stimulated, we see "red". If both our green and red-orange cones are simultaneously stimulated, our perception is yellow.The eye cannot differentiate between spectral yellow, and some combination of red and green. The same effect accounts for our perception of cyan, magenta, and the other in-between spectral colors.Because of this physiological response, the eye can be "fooled" into seeing the full range of visible colors through the proportionate adjustment of just three colors: red, green and blue.

• Contrast of TONE

• Contrast of HUE

• Contrast of SATURATION

• Contrast of EXSTENSION

• Contrast of TEMPERATURE

• COMPLEMENTARY contrast

• SIMULTANEOUS contrast

CONTRAST OF TONE...

Formed by the juxtaposition of light and dark values. This could be monochromatic

CONTRAST OF HUE

Formed by the juxtaposing of different hues. The greater the distance between hues on a colour wheel, the greater the contrast.

CONTRAST OF SATURATION

Formed by the juxtaposition of light and dark values and their relative saturations

CONTRAST OF EXTENSION.

Formed by assigning proportional field sizes in relation to the visual weight of a colour. Also known as the contrast of proportion. 

CONTRAST OF TEMPERATURE 

formed by juxtaposing hues that can be considered ‘warm’ or ‘cool’. Also known as the contrast of warm and cool

COMPLIMENTARY CONTRAST

formed by juxtaposing complementary colours from a colour wheel or perceptual opposites

Complementary

"The pairs of colours lying opposite in the colour wheel form the complementary contrast from a primary colour and the secondary (mixed) colour made of the other two primary colours. Yellow-violet displays the largest light-dark contrast, orange-blue the largest cold-warm contrast. Red-green have the same light intensity. The complementary contrast causes the brilliance of the colours to increase."- http://www.erco.com/guide_v2/guide_2/designing_w_90/colour_cont_1827/en/en_colour_cont_intro_5.php

LECTURE 4- Subjective Colour

What's strange about this cross above is that if you stare at it for 30 seconds then look at a wall or anywhere you will still be able to see the cross.


'...SUBJECTIVE COLOR means that a color changes in your head dependent on how your eyes and brain perceive it. A subjective color is the color it looks because of the way you see it.

On the other hand, OBJECTIVE COLOR means a color would be independent of the way humans perceive the color. Objective colors would be immutable, never changing colors independent of human perception.

NOTE:
(The word “Subjective” means existing in the mind and not independent of it.)
(The word “Objective” means existing independently of the mind or perception.)

HERE IS AN EXAMPLE of the difference between subjective objective color:
If color was truly objective your red car would always be the same color red independent of lighting conditions. But the way that the rods and cones work in your eyeball, and the way the visual cortex in the occipital region of your brain processes the way you see the color then your car is different under sodium lights, bright daylight, florescent light, dull evening light just before sunset, or halogen light. In this way the red color of your car is subjective color, not objective color. Objective color red would remain the same red no matter what situations it was seen in.

Probably the hardest concept to fully grasp about color is that color is all in your head. Literally. It's a sensation, just like touch. Like any other sensation it's (usually) caused by physical reality. But it doesn't have any physical reality of it's own--at least not outside your body. And--this is the hard part--color is not a property of the thing that's causing the sensation. In other words, grass is not green and the sky is not blue. Rather, they have physical properties that make you perceive green and blue, but even that's true only in some circumstances....' - http://answers.yahoo.com/question/index?qid=20101206152031AASIb3w