Slide 1

Color Communication in the Digital Age

The Language of Color

Presented by:Brian Ashe

Technical Consultant GDSCX-Rite

Slide 2

Color Communications

– What is color?

– Understand our limitations.

– How can we measure color?

– When is color “good enough”?

– What is the cost of good color?

Objectives

Slide 3

Identify This Color

Slide 4

Identify This Color

Slide 5

b

e

a

d

g

f

h

i

j

k

l

cm

n

o

p

q

rs

t

u

v

w

x

y

z

Which Color Is It?

Slide 6

b

e

a

d

g

f

h

i

j

k

l

cm

n

o

p

q

rs

t

u

v

w

x

y

z

c

Which Color Is It?

Slide 7

• Add density

• Increase detail

• Increase saturation

• Increase sharpness

• Needs more depth

• Add contrast

• Add density

• Balance the neutrals

• Make it “Pop”

• Chalky

• Grainy

• Make colors cleaner

• Match attached copy

• Needs warmth

• Reduce blue 2%

• Needs redder reds

• Colors are too strong

• It feels blown-out

• Does not have shine of transparency

• Just a ‘smidge / tad less’…

• Tone it down

• Too dull / too flat

• Too muddy

• Whiter whites but hold detail

• Fleshier flesh tones

• Give me more shape

• Needs to be commercially acceptable color

• Hold highlight

Ineffective Communication

Slide 8

Count the Dots

Slide 9

x

Afterimages

Slide 10

x

Afterimages

Slide 11

Retinal fatigue

– Brief exposure to strong colors leaves an after image

– Considerable rest may be needed to let the eye recover

The “I” Factor

Slide 12

Simultaneous Contrast

Slide 13

Simultaneous Contrast Experiment

Slide 16

Retinal fatigue

Background effects

– The fovea sees the greatest detail, but is still affected by the

rest of the eye

– Always be aware of your field of view

The “I” Factor

Slide 19

Retinal Fatigue

Background effects

Poor Color Memory

– Two objects must be viewed simultaneously in order to fully

judge their differences

The “I” Factor

Slide 20

6 2

Color Deficiency

Slide 21

Retinal Fatigue

Background effects

Poor Color Memory

Color Deficiency

– 1 in every 13 males suffers from red-green

colorblindness: 1 in every 300 females.

The “I” Factor

Slide 22

The Visible SpectrumLight is Color

Slide 23

Illuminant D65 – Daylight ~ 6500 K

Slide 24

Daylight Spectral Power Distribution Curves

Slide 25

Illuminant A – Incandescent ~ 2856 K

Slide 26

Illuminant F2 - Cool White Fluorescent ~ 4100 K

Slide 27

Daylight D75 Illuminant A

Cool White Fluorescent Horizon

Common Light Sources

Slide 28

Retinal Fatigue

Background effects

Poor Color Memory

Color Deficiency

Lighting conditions

– Failure to adopt standardized viewing conditions

often results in poor color decisions

The “I” Factor

Slide 29

A Incandescent

C Sunlight

D50 Daylight ( Horizon Sky Daylight )

D65 Daylight ( Average North Sky Daylight )

D75 Daylight ( North Sky Daylight – Sky Only )

F2 Cool White Fluorescent

F7 Broad Band White Fluorescent

F11 TL84

F12 Ultralume 3000

Some Standard Illuminants

Slide 30

– Our Eyes can be fooled

– Perceived Color may be Systematically Organized by:

– Hue (color family), Value (or lightness), and Chroma (strength)

– Color is Light: Light is Energy

– Light Sources distribute energy differently

– Perceived Color requires Light, Object, and Observer

– We must Control the Light to Manage our Perception of Color

– Our Eyes have Three Color Channels - - Red, Green, and Blue

What Have we Learned so Far?

Slide 31

Tristimulus Values – XYZ

Slide 32

David MacAdam’s Perception Ellipsoids

Slide 33

It seems that three numbers are required to

define a color in “color space”

Treat these numbers as if you were trying to find an address in an unfamiliar city.

Color Mapping

Slide 34

L*L*+b*+b*

--b*b*

+a*+a*--a*a*

L*L*+b*+b*

--b*b*

+a*+a*--a*a*

The CIE L*a*b* (1976)

Slide 35

L*L* == 42.6542.65a*a* == --23.0123.01b*b* == 10.5010.50

L*L* == 42.6542.65a*a* == --23.0123.01b*b* == 10.5010.50

L*L* == 42.6542.65a*a* == --23.0123.01b*b* == 10.5010.50

Tolerancing in L*a*b*

First a point is measured

Slide 36

Tolerancing in L*a*b*

DL* = ±1.00Da* = ±1.00Db* = ±1.00

DL* = ±1.00Da* = ±1.00Db* = ±1.00

Next limits are set

Slide 37

DE* = DL*2 + Da*2 + Db*2

Tolerancing in L*a*b*

Slide 38

Delta L*a*b* vs. Ellipses

Slide 39

Catch 22

Slide 40

Lightness

Chroma

Hue

What About L*C*h°?

Slide 41

L*C*h° is directly related to L*a*b*

They both plot on the same map

*Remember: Munsell described Hue, Lightness, and Chroma as ‘natural’ mechanisms by which we distinguish shade!

L* = L*C* = a*2 + b*2

h° = Arc Tangent (b* / a*)

Rethink L*C*h°!

Slide 42

C* h°h°

+a-a

+b

-b

+L

-L

How Does L*C*h° Fit?

90°

0°180°

270°

Chroma = Distance from gray

Hue = Angle from Red

Slide 43

L*L* == 42.6542.65C*C* == --23.0123.01h°h° == 155.47155.47

L*L* == 42.6542.65C*C* == --23.0123.01h°h° == 155.47155.47

L*L* == 42.6542.65C*C* == 25.2925.29h°h° == 175.47175.47

Tolerancing in L*C*h°

First a point is measured

Slide 44

Tolerancing in L*C*h°

DL* = ±1.00DC* = ±1.00DH* = ±1.00

DL* = ±1.00DC* = ±1.00DH* = ±1.00

Next limits are specified

Slide 45

While both L*a*b* and L*C*H* tolerance solids seem to

have similar shapes... the L*C*H* solid is free to rotate

about the center of color space.

Appearances Can Be Deceiving

Slide 46

Delta L*C*H* vs. Ellipses

Slide 47

Which would you choose?

Tolerancing: L*a*b* vs. L*C*h°

Delta L*a*b* vs. Ellipses

Delta L*C*H* vs. Ellipses

Slide 48

The CMC2:1 (Color Measurement Committee) calculation

dynamically scales and rotates tolerance ellipsoids in a manner

consistent with human perception.

Automatic Ellipsoids

Slide 49

CMC Tolerancing

Slide 50

L*a*b* CIE 1976 75%

L*C*H* CIE 1976 85%

CMC2:1 CMC, 1988 95%

Color Tolerancing - To Compare…

Slide 51

Modern Instrumentation

What to choose. When to use which and why?

Instrument Geometries – 0º/45º, Sphere, Multi-angle

Colorimeters vs. Spectrophotometers

Transmission vs. Reflection

Slide 52

Is a three-filter, tri-stimulus device

lamp

aperture

filtersreceiver

lampoptics

Colorimeter

Slide 53

How it views the spectrum

Colorimeter

Slide 54

lamp

aperture

filters

receiver

lampoptics

Spectrophotometer

Slide 55

Spectrophotometer – The Spectrum

Slide 56

Provides the “fingerprint” of the color

Gives all of the information of a colorimeter

and more…

– Required for formulation

– Identifies metamerism

– Best QA tool

Color Control - Spectrophotometry

Slide 57

Instrument Geometry – Why use What?

What to choose. When to use which and why?

Instrument Geometries – 0º/45º, Sphere, Multi-angle

Colorimeters vs. Spectrophotometers

Transmission vs. Reflection

Slide 58

Single angle (45°/0°)

lamp

receiver

lamp

Instrument Geometries - 0º/45º

Slide 59

Sphere (D8°)

lamp

Sampleviewing port

Specular port

8°8°

baffle

Instrument Geometries - Spherical

Slide 60

Multi-angle (15°/25°/45°/75°/110°)

lamp

75°

110°

45°25°

15°

Specularangle

Instrument Geometries – Multi-angle

Slide 61

Reflection from Surface (gloss)

Air

Resin

Reflection from Metal Flake

Aluminium FlakePigment Particle

Metallic Additives

Slide 62

Primary Types of Light Distribution

Slide 63

Gloss

Slide 64

Preparation, Presentation, Preservation

Be Consistent Manage variables

Train carefully

Keep things clean

Communicate

Draft clear procedures

Anticipate

Slide 65

Thank youPRESENTED BY

Brian AsheTechnical Consultant GDSC

X-Ritebashe@xrite.com

Please remember to turn in your evaluation

sheet...