lecture (2 and 3) : color physics and theories · 2020-03-24 · main color theories in design :...

by : Assis . Lec SEEMA K. ALFARIS

3rd Year Architecture 2018/2019 First Semester

Lecture (2 and 3) : color physics and theories

• Color perception(history of color)

• Color perception(spectrum+ Light)

• The Optical System

• Modifiers of light

• Color terminology (vocabulary)

Lecture subjects :

• Color mixing theories

• Color main theories

• In 1665, (Sir Isaac Newton) the first scientist who prove that (the color is a

function of light) and it’s a natural part of the sunlight (white color) .

• He passed a beam of sunlight through a prism .

• He identified the basic colors as the “Visible 7”: red, orange, yellow, green, blue,

indigo, and violet

Color perception(history of color) :

• Newton carried his experiment one step further by utilizing a second prism to mix

the waves back into sunlight .This Confirms the fact that color is basically made up

of light and that when “colored” lights are mixed ,the result is (white light).• So, he proved that mixing lights of all colors produces white.

Color perception(history of color) :

• Color is based on light .

• Light : is the electromagnetic rays , which contain Gamma rays , X-rays ,

Ultraviolet , visible light , infrared, and radio waves .

• Color : is a (physical phenomenon) , a specific visual sensation produced by

visible radiation of light, or “Color stimulus.” , Color stimulus occurs when light

from a natural or artificial source is interrupted by an object or a dust particle.

• The Visible Light that Newton discover : is the electromagnetic rays we can see ,

its ranging from red (rays most bent) through orange, yellow, green and blue to

violet (rays least bent).

Color perception(spectrum+ Light) :

Color perception(Vision + Light) :

high

low• Wavelength and hue are the color‘s

perception.

• Each hue(from the visual spectrum)

has a certain range of wavelength,

with red , having the longest

wavelength , and violet having the

shortest of the range wavelength .

• The physical difference between (radio waves, infrared, visible light, Ultraviolet,

and X-rays) is the wavelength.

Color perception(Vision + Light) :

Shortest range= violet Longest range= red

• The eye is an optical system that directs visible luminous radiation to the retina

(light-sensitive ) layer which contains the individual receptors (the rod and cone

cells) .

The Optical System:

• The eye and light are in direct relation with one other. Since color only exists in

the brain, it is the eyes job to receive the reflected light waves and transmit the

wavelengths to the cerebral cortex.

https://en.wikipedia.org/wiki/Photosensitivity

The Optical System:

The Retina : is a thin layer oftissue that lines the back of theeye on the inside. It is locatednear the optic nerve. Thepurpose of the retina is toreceive light that the lens hasfocused, convert the light intoneural signals, and send thesesignals on to the brain for visualrecognition.

The Optical System:

• These individual receptors ( the

rod and cone cells), which decode

the physical stimulus and translate

it into a physiological one

(feelings) .

• The rods differentiate between

light and dark, only registering

light’s intensity, while the cones

differentiate between colors .

• The color of an object or surface is determined by its reflected or

transmitted light.

• White is often described as the reflector of all colors,

• while black is described as the absorber of all colors.

Modifiers of light :

• Every object absorbs some light

and reflects some light. If the light

is not the same color as the object

it can not reflect light, and the

object would appear black.

• An object that the eye perceive it as red or blue ,if we spot on it a white light , it

will absorbs all the colors except its same color ( red or blue), which it reflects.

NOTE : Only red and blue (lights waves) are reflected back to the eye after all

other wavelengths are absorbed by the red , blue surfaces .

Modifiers of light :

• For example, if white light falls on a red

or blue surfaces, that surface will

absorb all the wavelengths except the

red and blue ones, which are reflected

back to the eye, allowing us to perceive

red and blue colors.

Color terminology (vocabulary ):

1. Color wheel consists of :

• Primary colors

• Secondary colors

• Tertiary colors

2.Hue.

3.Value (tint and shades) .

4.Saturation(tone) .


1.Color wheel :

• The color wheel is a visual representation of color theory .

• One of the basics tools for combining colors, its represent an organization of color huesaround a circle, which shows therelationships between primary colors,secondary colors, tertiary colors .

Color wheel consists of :

• Primary colors

• Secondary colors

• Tertiary colors

The most common color wheel isthe twelve (12) huewheel(artistic)model .A colorwheel could have as few as sixhues or as many as 24.48 96 ormore.

Color wheel (primary colors ):

• Group of colors (yellow, red, blue) whichrepresent the hues that form color wheelbase.

• These basic colors can be mixed to produce all other colors.

• The primary colors cannot be made bycombining other colors.

• Mixing primary colors : Red, yellow, blue (RYB) .

Pieter Mondrian( Dj stjil style )

• In this style only the primary colors are used, red, blue and yellow.

• In terms of shape, only the squares and rectangles can be used.

• In terms of lines only straight horizontal and vertical lines


• Colors that are made by mixing two adjacent primary colors ( a 50 percent the mixing any two primary colors.)

Color wheel (secondary colors ):primary

Primary SecondaryCyanine(Blue)+ Magenta(Red) = VioletMagenta(Red)+Yellow = OrangeYellow + Cyanine(Blue) = Green

Color wheel (tertiary colors ):

• Intermediate , or Tertiary , colors are created by mixing a primary and a secondary colors .

• for example , the tertiary color produced when mixing the primary color( blue) with the secondary color( green) , is called 'blue-green'.

Red-Orange

Yellow-Orange

Yellow-Green

Blue-Green

Blue-Violet Red-Violet

The Main Qualities of Color :1. Hue

2. Value (Tint ,shade)3. Saturation (Tone)

In this color wheel , we have 4 splittedcircles , the 12 colors . Each circlerepresent a certain term (hue , tint , toneand shade ) .


1. Hue:• Another name for color .• A hue is any color on the color wheel (red, yellow, blue,

etc).• A hue is the purest form of a color.• Hues are colors that have not been mixed with white, gray,

or black . • White, Black and Grey are never referred to as a Hue.

Color terminology (vocabulary ):Hue(pure color)

2. VALUE (Tint , SHADE) :


• Refers to the lightness or darkness of a color.

• It indicates the quantity of light reflected.

• nine graduations of value scale betweenwhite and black.

• The dots (middle value) appear darkeragainst a light background and lighteragainst a dark one.

• Tint in the circle of colors next to the hues . • Result of adding more white to an existing color.• The hue may be mixed with just a touch of white or

with so much white that the hue is very faint .

Tint

Hue

Shade


TINT :(Value)

Shade :


• A shade is the hue mixed with black .• Just as with the tines , the hue may be mixed

with just a touch of Black or more .

Tint

Hue

Shade

(Value)


3. Saturation (Tone)• Saturation or (Chroma) defines the brilliance

and intensity of a color.• It means the brightness or dullness of hue.

• It showed When a pigment hue is “toned,” both white and black (gray) are added to the color to reduce the color’s saturation.


Tint

Hue

(Value)

Shade

Tone :• A tone is the hue mixed with any amount

of gray .

(Saturation) tone

A simple diagram

shows that :

Tints, tones, and

shades can be

produced by adding

white, gray, or blackto a pure hue

• Here the Hue is (violet ).

There are 60+ colors here, but all of

them are Violet - hued colors.

• Chroma changes from left-to-right

Low - chroma colors are on the left...

Mid -chroma colors near the center...

High -chroma colors on the right.

• Value changes from bottom-to-top:

Low values (shades) near the bottom

High values (tints) near the top.

Example about value and saturation

Example about value and saturation

• Virtually all our visible colors can be produced by utilizing some combination

of a 3 primary colors. They are mixed in specific pairs to create secondary

colors.

There are 2 theory of color mixing models , They are:

1. Additive theory(RGB).

2. Subtractive theory (CYM).

Color Mixing models :

1. Additive colors RGB :

• The additive, or light theory deals with radiated and filtered light.

• In this process color is created by adding light (red, green & blue) to dark background. (Primary colors)

• Secondary colors primary Cyan (C) , Magenta (M),

yellow (Y) .

• Adding all three additive primaries together or

overlapping them ,that will creates gray or white light.


• The main purpose of the additive colors or light Theory is for there presentation ofcolored images in electronic systems ,such as televisions ,computers ,cellphones , webcolors and video projectors.

• Additive color devices, such as television, work by having the capability to generate an image composed of red, green, and blue light

• Care should be taken in the use of coloredlights ,especially where colors selections areimportant ,because these lights can distortreal color and cause eye irritation.

• The mixing of colored light is usedin theaters stages (interior) , cafésand restaurants environments ,alsoit used in open spaces stages(exterior) , However , it createsimilar stage effects.

2. Subtractive colors CMY(K):• The subtractive, or pigment theory deals with how white

light is absorbed and reflected off of colored surfaces• Typically illuminated by white light .

• Used in inks for printing with a black (K) added , because(CYM ) pigments and inks rarely give deep, rich blacktones by themselves (they tend to make a muddy brown).

• Subtractive Primary colors are: Cyan (C), Magenta

(M), yellow (Y) (the secondary colors of RGB)• Colored Pigments absorb light and reflect only the

frequency of the pigment color.• Each subtractive colored pigments removes one of the

additive primary colors from the reflected or transmitted image.


Subtractive or Pigment Theory is used in printing and painting.

• The CMY (cyan ,magenta ,yellow ) color model is a subtractive model that is used in color printing.

• A majority of the world’s printed materials is produced by this method of color mixing.

Main Color theories in design :

1.Newton's Hue Circle.

2. Itten's Color Wheel.

3.Munsell's Color Order .

4.Ostwald Color theory .

5.The Pantone Color System.

• Many attempts have been made to establish methodologies to

evaluate the advantages of certain color combinations ,and the

main color theories in design , are as the following : .

• Newton was the first to understand that colors did not lay on linear chart ,but

rather existed in a continuum.

• Isaac Newton split white light in to seven colors- red , orange ,yellow ,green ,blue

,indigo ,violet , and he arranged them on a disk in proportionate slices such that

the spinning of the disk would result in the color white.

Main Color theories in design : Hue circle :

In his attempt to develop a theory of color :

In his attempt to develop at theory of color:

• , The hue circle is represented by white at

the center . and the hues arranged in order

around the disk.

• Each hue is given a weight ,or proportion

,that balances it within the system.

• Newton closed his system through a mix

between red and violet that did not appear

in his natural primary spectrum.


• The Ostwald system creates a color space based ondominant wavelength, purity, and luminance, mapping thevalues of hue, saturation and brightness.

• The full colors are arranged around a complete circle starts out with four basic colors: yellow to the north; red to the east; blue to the south; and yellow-green to the west.

• With these eight colors, Ostwald constructs 24 color-hues with equal spacing and numbers them from

OSTWALD COLOR THEORY(1916) :

• The Color Harmony Manuals were published beginning in 1916,


• Thus the point in the Ostwald color space is represented by values C , W, and B to represent the percentages of the circle.

• The American Albert Munsell developed a system (three dimensional ) model

of color analysis based on the methodology that for each color hue , value ,

and Chroma.

The Munsell Color Order System(1921):

• In Munsell's system:

1. Hue is arranged around the perimeter of a

sphere,

2. Value as it moves from the top pole(light) to

the bottom (dark) .

3. Chroma as it moves toward the center.


• Munsell established numerical scales with visually uniform steps (notation)

for each of these attributes , that made it easy to identify any color in his

system.

Example :Using the Munsell numerical scale HV/C, for the color (Red ) would have the Munsell notation (5R 6/12) =1. (5 )is the hue (red).2. ( 6 ) is the value .3. (12 )Chroma .

• In this notation, each color has a logical relationship to all other colors. This

leads to endless creative possibilities in color choices, as well as the ability to

precisely communicate these choices.

• Munsell Color Order System is called ,

the Color tree.

• The notation for a neutral color is written: NV.

• The Chroma of a neutral color is zero, but it

is customary to omit the zero in the notation.

• The notation N 1/ denotes a black, (a very

dark neutral), while N 10/ denotes a white,( a

very light neutral). This notation for a middle

gray is N 5/.


Itten's Color Wheel (1961)

Main Color theories in design:

• The six colors(primaries and secondaries ) mixed carefully ,it will generate a

12 sequenced colors.

• Johannes Itten developed his color wheel based on

primary colors of (red , yellow ,and blue) , The three

primary colors placed in an equal triangle ;yellow at the

top ,red is the lower right, and the blue in the lower left.

•

• About this triangle Itten in scribed are hexagon

,resulted from mixing the primaries to obtain the three

secondary colors as the following: yellow + red =

orange, yellow + blue = green , and red + blue =violet .

• Itten didn’t believe in further expanding the color wheel to 24 – or 100 hue wheels.

• He believes that the dilution (decrease) of the naming system in his establishment

it will make it easy to identify every color distinctions.


Note : This 12 color wheel is represent the base for

all schemes

• Pantone is a corporation that began as a

commercial printing company in the1950s.

• This system is used in a variety of

industries, like : printing, it is sometimes

used in manufacture of colored paint,

fabric, and plastics.

• Pantone’s system consists of approximately

1,114 ink colors that are produced from 13

base pigments (15 including white and

black) mixed in specific amounts.

The Pantone Color System(1962):


• However, it is best known for its color

matching system(PMS),as seen in the

Figure.

• The idea behind the (PMS) is to allow

designers to "color match" specific colors

when a design enters production stage,

regardless of the equipment used to

produce the color.

• Each color is identified by a three – or

four digit number followed by a C, M, or

U, such as PMS ( 2448 U).

• The letters following the number refer to

the type of paper they are printed on

,such as C=coated, M=matte ,and

U=uncoated.

• Since 2000, the Pantone Color Institute declares a particular color "Color of the Year".

• Pantone recommends that PMS Color Guides be purchased annually, as their inks

become yellowish over time

• The Pantone system can be used with the CMY mixing process as well as the screen

based RGB process.

Thank you …

lecture (2 and 3) : color physics and theories · 2020-03-24 · main color theories in design :...

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