Color design - Maureen Stone

Transcription

Color design - Maureen Stone
AIM Institute & Gallup Organization
Omaha NB
9/14/2007
Color design
From seeing red to feeling blue
Maureen Stone
StoneSoup Consulting
Woodinville, WA
www.stonesc.com
Published by AK Peters, 2003
Color in Information Display
Graphical presentation of information
• Charts, graphs, diagrams, maps, illustrations
• Originally hand-crafted, static
• Now computer-generated, dynamic
Color is a key component
www.nps.gov
Emotional Design
Emotion, not just function
Victoria Interrante and Chester Grosch, U. Minnesota
Image courtesy of Siemens
Image courtesy of the
American Museum of
Natural History and the
San Diego Supercomputing Center
• Attractive things work better
• Compensates for lack of function
• People choose with their emotions
Don Norman, Emotional Design
Image courtesy of Los Alamos National Lab
Maureen Stone, StoneSoup Consulting
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AIM Institute & Gallup Organization
Omaha NB
Emotional Color?
Color & Language
Can we predict behavior from color preferences?
Colorgenics Profile, Lüscher Colour Test
Do colored environments affect behavior?
• Calm or stimulate behavior?
• Make the room feel warmer or cooler?
• Affect what and how much people buy?
Are there inherent color “messages?”
• At a psychological level?
• At a cultural level?
• At a marketing level?
9/14/2007
Language for color
Black, white, gray
• Color names (simple & complex)
Red, green, blue, yellow
• Basic names (Berlin & Kay)
Orange, purple, brown, pink
Color in language
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•
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Seeing red, red-letter day
Feeling blue, true blue
Green-eyed monster
Purple prose, purple heart
Yellow streak, white feather
Black-hearted, in the black
FactMonster.com
Colorful language
Color and Moods
ColorVoodoo, Colorcom
How important is color?
Does color add any information?
Which would you rather look at?
People LIKE color
Visualization of isoelectron density
surfaces around molecules
Marc Levoy (1988)
Maps courtesy of the National Park Service (www.nps.gov)
Maureen Stone, StoneSoup Consulting
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AIM Institute & Gallup Organization
Omaha NB
9/14/2007
Norman’s Design Levels
Visceral
• “I want it…what does it do?”
• Immediate emotional response
Behavioral
People Like Color
• User, task, solution
• Functional design
• Feels good to use
Reflective
• Message, culture, meaning
• Reflects self-image
• Thought & emotion
“Made in the Shade”
Color Marketing Group
“Good ideas executed with superb craft”
—E.R. Tufte, Envisioning Information
What creates good
color design?
Aesthetics
Perception
Materials
Materials: Pigments & Paints
Materials: Dyes
Organic molecules
Scattered light
• Biological origin (snails, bugs,
plants, etc.)
• Synthetic (William Perkin)
• Dyed pigments are “lakes”
The Bright Earth, Philip Ball
Maureen Stone, StoneSoup Consulting
Mauve, Simon Garfield
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AIM Institute & Gallup Organization
Omaha NB
9/14/2007
Print & Film
Light
Summed spectra
Layered color
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•
•
•
CMY primaries
Film: dye layers
Print: Halftone patterns
Black for contrast
• RGB primaries
• Displays, projectors
• Basis for digital color
LCD Display
Materials
Perception
CRT Display
Aesthetics
Physical World
Visual System
Mental Models
Lights, surfaces,
objects
Eye, optic
nerve, visual
cortex
Red, green, brown
Apple, leaf, bark
Stop, go, state park
Warm, cool, neutral
Attractive, ugly, blah
Color design
Powerful, nurturing,
…
“Perceptual” Color Spaces
Physical World
Visual System
Mental Models
Light
Energy
Cone
Response
Opponent
Encoding
Perceptual
Models
Appearance
Models
Spectral
distribution
functions
Encode as
three values
(L,M,S)
Separate
lightness,
chroma
Color
“Space”
Color in
Context
F(λ)
CIE (X,Y,Z)
(A,R-G,Y-B)
Hue,
lightness
saturation
Adaptation,
Background,
Size, …
CIELAB
Munsell
(HVC)
CIECAM02
Hue
• Color’s “name”
• Angular scale
Lightness (brightness)
• Linear scale
• Black to white
Chroma (saturation)
• Intensity or purity
• Radial scale
Lightness
Chroma
Hue
Maureen Stone, StoneSoup Consulting
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AIM Institute & Gallup Organization
Omaha NB
9/14/2007
Art & Design
Munsell Atlas
Hue (color wheel)
• Opposites complement (contrast)
• Adjacent are analogous
• Many different color wheels*
*See www.handprint.com for examples
Chroma (saturation)
• Intensity or purity
• Distance from gray
Value (lightness)
• Dark to light
• Applies to all colors, not just gray
Wucius Wong, Principles of Color Design
Courtesy Gretag-Macbeth
RGB: Pseudo-Perceptual Models
HLS, HSV (HSB)
NOT perceptually accurate
Do NOT predict perceived lightness
(Value or Luminance)
“Color is the most relative medium in art.”
—Josef Albers, Interaction of Color
Hue: 110
Sat: 255
Lum:128
yellow
Hue: 160
Sat: 100
Lum:128
Effective Color Design
“Good painting, good coloring, is comparable to
good cooking. Even a good cooking recipe
demands tasting and repeated tasting while it is
being followed. And the best tasting still
depends on a cook with taste.”
—Josef Albers
Use color for a purpose
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Identify your information & messages
Identify its function
Assign relative importance
Map colors accordingly
Design using contrast & analogy
• Contrast emphasizes
• Analogy groups
• Legibility, attention & layering
Design, test, evaluate
Practice, practice, practice
Maureen Stone, StoneSoup Consulting
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AIM Institute & Gallup Organization
Omaha NB
Envisioning Information
9/14/2007
Fundamental Uses
“… avoiding catastrophe becomes the first
principle in bringing color to information:
Above all, do no harm.”
—E. R. Tufte
To
To
To
To
label
measure
represent or to imitate reality
enliven or decorate
www.edwardtufte.com
Color and Function
Color and Function
To label
To evoke nature
• Primarily hue variation
• Associated with color names
• Metaphor, symbolic
• Illustration: distilled experience
To measure
• Vary lightness & chroma
• Map to data distribution
ColorBrewer
Cynthia Brewer, Pennsylvania State University
Color and Function
To decorate, beautify
• Emotional design
• Visceral & reflective
Contrast and Analogy
Contrast & Analogy
• Contrast (difference) separates
• Analogy (similarity) groups
Hue, chroma, value
Maureen Stone, StoneSoup Consulting
Value only
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AIM Institute & Gallup Organization
Omaha NB
Get it right in black & white
9/14/2007
Controls Legibility
Value defines shape
• No edge without lightness difference
• No shading without lightness variation
Value difference (contrast)
• Defines legibility
• Controls attention
• Creates layering
Creates robustness
colorusage.arc.nasa.gov
• Across viewers
• Across media
Can you read this?
Can you read this?
Can you read this?
Must have value contrast,
NOT just hue contrast
Can you read this?
Creates Layers
In brief
“Get it right in black & white”
Use neutral backgrounds
Urgent
Context
Normal
Normal
Context
Urgent
Context
Normal
Urgent
Context
Normal
Normal
Context
Normal
Context
colorusage.arc.nasa.gov
• Grays or near gray
• RGB all nearly equal
• Prefer light backgrounds
Avoid overly saturated colors
• RGB: No values are zero
• Exception: yellow
Use hue contrast sparingly
• Small differences are fine
• If many hues, then use
similar value, saturation
Tableau Case Study
Design color for Tableau Software
“Visual Analysis for Everyday Data”
Task
• Design color palettes
• Collaborate on color selection UI
Goals
• Aesthetic “business graphics”
• Robust across displays and users
• UI encourages good practice, but allows choice
Maureen Stone, StoneSoup Consulting
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AIM Institute & Gallup Organization
Omaha NB
Color design tasks
Categorical color palettes + UI
• Color as label
• Distinctly different, similar visual weight
• Scatter plots, line graphs, bar charts, text
Quantitative color palettes + UI
• Color as quantity
• Sequential and diverging scales
• Heat maps, scatter plots (but could be any above)
Formatting colors + UI
9/14/2007
Global Issues
Subtlety vs. robustness
What can we assume about the display?
Not calibrated (except mine)
Clarity vs. expressiveness
How many colors?
What about the “color blind?”
Simplicity vs. power in the UI
Optimized for good practice
Data-to-color control, not color control
• Color to decorate (also group and label)
• Row, column and header shading
• Annotations (lines and text)
Categorical Colors Issues
Sample pages
Color palettes
• How many? Algorithmic?
• Extensible? Customizable?
Color appearance
• As a function of size
• As a function of background
Robust and reliable color names
UI to encourage good practice
― But, must allow for personal expression
Sample pages
Categorical Colors
10 basic colors
• Simple names
• Increase number with
lightness variation
Designed to balance
• Legibly colored dots, lines
and text
• But not too gaudy for bars
• Tasteful, yet colorful
Questions
• What are parameters for legibility?
• Can we adapt color to size?
• Richness vs. clarity
Maureen Stone, StoneSoup Consulting
8
AIM Institute & Gallup Organization
Omaha NB
Tableau names
Basic names (11)
• Black, white, gray
• Red, green, blue, yellow
• Orange, purple, brown,
pink
9/14/2007
Palette-based UI
1. Select whole palettes
2. Individual colors from different palettes
3. Standard color picker
Tableau names (10)
• Minus black & white
• Plus teal
• Yellow => gold
Formatting Colors
…Fix this
Formatting Color Issues
Taste and style
• Aesthetic, professional
• Lots of choices
Shading colors
• How light can we go?
• Visibility in the UI
Annotation colors
• Text legibility
• Different from data colors
• Harmonious with formatting, data colors
Limited space and time for UI implementation
Maureen Stone, StoneSoup Consulting
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AIM Institute & Gallup Organization
Omaha NB
UI Evolution
Maureen Stone, StoneSoup Consulting
9/14/2007
Expanded Palette
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AIM Institute & Gallup Organization
Omaha NB
9/14/2007
Quantitative Color Issues
Color sequences
• What colors, what sequences?
• Continuous or quantized? (and how?)
• Work at all sizes, and in isolation
Real numeric data
• All distributions, including outliers
• Can’t visualize the histogram
UI to encourage good practice
• UI must be simple, not intimidating
• Users not expert in color or statistics
Ramp Design
Color Brewer
Start with Brewer ramps
• Available as RGB
• Not calibrated
Modify
• For sRGB
• Eliminate darkest colors
• Reduce hue shift
Interpolate
• Custom Python code
• CIELAB, RGB
• Piecewise linear
From ColorBrewer
www.colorbrewer.org
Sequential Ramps
Maureen Stone, StoneSoup Consulting
Diverging Ramps
11
AIM Institute & Gallup Organization
Omaha NB
Data Distribution
9/14/2007
Proportional Distribution
Skewed Data
Slightly negative
www.tableausoftware.com
Mapping Census 2000: The Geography of U.S. Diversity
Full Range
Stepped
Skewed Data
Skewed Data
Threshold
Skewed Data
StoneSoup Consulting, 2005
Maureen Stone, StoneSoup Consulting
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AIM Institute & Gallup Organization
Omaha NB
Quantitative UI
9/14/2007
Color Vision Deficiencies (CVD)
Non-standard cone (SML) response
• Genetic
• Medical
• Mild to missing
Three modes
• L-weak (protanope)
• M-weak (deuteranope)
• S-weak (tritanope)
Modeled in opponent space
• Achromatic axis
• R-G and Y-B axis
Incidence of CVD
Monochromacy - 0.003%
Dichromacy
• Protanopia 1%
• Deuteranopia 1.1%
• Tritanopia 0.002%
Vischeck
Simulates dichromatic color vision deficiencies
• Web service or Photoshop plug-in
• Robert Dougherty and Alex Wade
vischeck.com
Anomalous trichromacy
• Protanomaly 1%
• Deuteranomaly 4.9%
• Tritanomaly -
Total - 8.005%
R. W. G. Hunt. Measuring Colour. Fountain Press,1998.
Maureen Stone, StoneSoup Consulting
Deuteranope
Protanope
Tritanope
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AIM Institute & Gallup Organization
Omaha NB
Smart Money
9/14/2007
Tableau Palette
protanope
deuteranope
luminance
Additive Color
Accommodation
Combine red, green, blue lights
No color set that works for all viewers
Even accommodating most common is limiting
Options:
Primaries
• red
• green
• blue
• Minimize dependency on color
• Double encode
• Provide choices/customization
Image
STOP
White
light
White
light
White
light
Subtractive Color
Filter white light to modulate R, G, B
Primaries
• cyan
• magenta
• yellow
Image
Color Filters
white light
Maureen Stone, StoneSoup Consulting
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