Using Color to Communicate,Not to Decorate

LeRoy Bessler PhDDentaQuestVisual Data Insights™Le_Roy_Bessler@wi.rr.com

SAS is a registered trademark or trademark of SAS Institute Inc. in the USA and other countries. ® indicates USA registration. Other product and brand names are trademarks or registered trademarks of their respective owners.Visual Data Insights is a trademark of LeRoy Bessler PhD.

Too many to list.See my “Principia Color” tip sheetin the Proceedings Addenda Section

Key Take-Aways

• image + precise numbers =quick, easy inference + reliable inference

• ODS SGPLOT VLINE Overlay Color Chart

My Favorite Multi-line Plot Solution

• Eliminates any need for a legend• A Magnificent SolutionCode to create a similar result is at:http://www.lexjansen.com/mwsug/2012/DV/MWSUG-2012-DV13.pdf

My Favorite Multi-line Plot Solution

S & P Index By Month 1988 to 1991

Access to Color ExcessAll the ways to color a PROC PRINT table.SAS code isin the paper. Capabilities also for PROCTABULATE and REPORT.No use PROC TEMPLATE.

Let me be yourSAS Color Therapist

Use Colorto Communicate

When you evaluate the color distinguishability on these slides—In slides, color distinguishability isbetter than when graphs are printed.• Projection magnifies the color areas.• Printed color does not shine

like monitor color.

Assure colors are distinguishableDifficult/Impossible to distinguish:• thin lines• thin or tiny text• very small plot markers• very small legend samples

Typical Uses of Color in IT• Color coding (legends, traffic lighting*, etc.)• Emphasis• Decoration* “traffic lighting” is a communication problem for some viewers—details later

Common Bad Uses of Color in IT• Textured Backgrounds• Color Gradient Backgrounds• Image Backgrounds

ALL impair the readability of foreground text,and add ZERO communication value

Common Bad Uses of Color in IT• legend using a color gradient

rather than discrete colors• human eye can reliably distinguish only five

shades of the same hue,plus black and white

Emphasis Options for Colorless Text• Bold• Italics• Underline (if not a web context)• (used sparingly) ALL CAPS

A PopularColor Communication Failure

Commonest Color Blindness:Red = Green

Alternative to “Traffic Lighting”

NOTE: Use light shades of red and blue with black text. Full strength OK with white text.SAS code is in the paper.

Pop. Density (per sq. km.) Change in Counties of Republic of Ireland, 1901‐1996Highlighted Spatial Population Table of County Name, Density Change, & 1996 Density

An Alternative to Traffic Lighting: augmented with light shades of the signal colors.

Pop. Density (per sq. km.) Change in Counties of Republic of Ireland, 1901‐1996Highlighted Spatial Population Table of County Name, Density Change, & 1996 Density

Color ReadabilityColor Distinguishability

Make Colored Text Thicker• this is black Arial text• this is red Arial text• this is bold red Arial text

Dots at 28 pt, 28 pt bold, 56 pt bold.   . . . .   . . . . ..   . . . .   . . . . .

.   . . . .   .. . . .

.   . . . .   . . . . .

.   . . . .   . . . . .

.   . . . .   .. . . .

Compare Readabilitywhite grey blackyellow orange red magentagreencyan blue medium blue dark blue

Compare Readabilitywhite grey blackyellow orange red magentagreencyan blue medium blue dark blue

Five-Cluster Distribution of 532 VIEWS Members by County in 1999

1-1014-2429-3043-49

61

human eye cannot reliably distinguish more than fives shades of one hue

Use Color to Communicate, Not to Decorate• If your graph does not require color (e.g.,

for a legend to be able to distinguish different plot lines, pie slices, or bars),best color combination is black & white

• If not using white, try yellow.• If you don’t like yellow, try cream

Use Color to Communicate, Not to Decorate• It’s not an accident that books & newspapers

are printed black on white

Color Use

necessary

harmless

confusing

What do the same color bars have in common?

When to Use Color• No data levels or categories:

black & white• Few levels or categories:

gray shades maybe• Many levels or categories:

color necessary

Benefits of “Boring” Black & White• Faster, cheaper, more reliable• Easier to use

– simpler equipment– no agonizing over color strategy

• More copyable(more, cheaper, faster copiers):Useful Documents Get Copied

Michael Turton on Color:• works better with space around it• prioritizes information,

whether meant to or not• can guide the viewer

How or whether to use color:What purpose does this color serve?

How or whether to use color:Unless for a legend* or color coding,the best color combinationis ALWAYS black & white.*When doing a multi-line plot without an on-chart y-value table, it isadequately rendered in black & white with differently shaped plot symbols.

All About Legends

Legend Sample Size DefectsSample Sizes Too Small—Difficult or Impossible to distinguish:• Excel Example: pie chart legend

Anti-Communicative Excel Pie ChartIn a Word Document or Printed,unusable legend: BrandB or BrandE?

Figure 7: Excel Pie Chart With Legend.Legend Color Samples Are Too Small.

5%20%

5%

11%19%

40%

BrandABrandBBrandCBrandDBrandEBrandF

Anti-Communicative Excel Pie ChartExcel does not supportadjustment of size of legend colors

Figure 7: Excel Pie Chart With Legend.Legend Color Samples Are Too Small.

5%20%

5%

11%19%

40%

BrandABrandBBrandCBrandDBrandEBrandF

Communicative-Effective Pie ChartWith Legend, Made With SAS/GRAPH

For code similar to that used for above, see:http://support.sas.com/resources/papers/proceedings12/235-2012.pdf

► ODS Graphics Pie Chart with Legend (or Labels) requires Graph Template Language► See my SAS Global Forum 2014 paper for what an ordeal this can be—if you are fussy about design

Legend Sample Size ControlSAS/GRAPH vs. ODS Graphics

• SAS/GRAPH – absolute control of size• ODS Graphics:

– pre-Version-9.4 bar chart legend fails– V9.4 AUTOITEMSIZE option of the

KEYLEGEND statement fixes problem• AUTOITEMSIZE sets color sample size

to match the font size of the description

V9.3 ODS Graphics – Tiny Legend Samples

V9.3 SAS/GRAPH - Successful Legend

V9.4 ODS Graphics without AUTOITEMSIZE

V9.4 ODS Graphics with AUTOITEMSIZE

Bar Chart Legend Sample SizeUpdate for ODS Graphics

V9.4 TS1M3, expected in July 2015,provides excellent controls:• SCALE – Scale color swatch by a factor• FILLHEIGHT –height of color swatch• FILLASPECT –aspect ratio of color swatch

(including “Golden”)

“3D” bars, legend colors ambiguous to my eye

Only 2D bars, but legend colors unambiguous

• For line charts and point (scatter) charts,ODS Graphics has size controlsfor line thickness & marker/symbol size—No Problem

ODS Graphics Plot Legends OK

Usable ODS Graphics Plot Legend

• Image for quick, easy inference• Precise Numbers for reliable inference• No Need for a Legend• Color-coded, color-coordinated

plot with on-chart table = LegendA Magnificent SolutionCode to create a similar result is at:http://www.lexjansen.com/mwsug/2012/DV/MWSUG-2012-DV13.pdf

My Favorite Multi-line Plot Solution

S & P Index By Month 1988 to 1991

Too many to list.See my “Principia Color” tip sheetin the Proceedings Addenda Section

Key Take-Aways

See the Paper for:• Color Naming Systems• Color Samples• Code to generate large number of samples

– colors– text-background color combinations

• Brief discussion of transparent colors andreferences for more & better informationabout them

Your questions, comments, and ideas about communicating with color are always welcome:

LeRoy Bessler PhDMequon, Wisconsin, USA Visual Data Insights™Le_Roy_Bessler@wi.rr.com

Visual Data Insights is a trademark of LeRoy Bessler PhD.

Do You See What I See (or Saw)?• Differences in human perception:

She sees brown. He sees green.Notice how hard it is to assessthe color of that thin text?

• Here is a solid block of it:

Color Variance Due To Technology• Monitor uses RGB colors, Printer uses CMYK• Also, “transmitted” color vs. reflected color• Monitor vs. Projector• Desktop vs. Laptop Monitor• LED vs. CRT Projector• Projectors require color tuning• PC color vs. Mac color

Beware of SAS Color Names

Above example used an earlier version of SAS.In V9.4, C=LightPink yields a lighter color than that above, but STILL darker than C=Pink.