1. Color in Visual Design CS 4390/5390 Data Visualization Shirley Moore, Instructor September 10, 2014

2. Goal Develop a theory-based approach to how color should be used in design Aim for clarity and efficiency of visual queries Aesthetics OK too but secondary

3. Rod and Cone Cell Distribution in Human Retina Image credit: http://www.webexhibits.org/causesofcolor/1G.html

4. Electromagnetic Spectrum

5. Visible LIght

6. Sensitivity Functions for the Three Types of Cone Cells

7. Opponent Process Theory: 3 Color-Opponent Channels in V1

8. Color “Blindness”

9. Color Terminology

10. Luminance Contrast

11. Simultaneous Constrast

12. Simultaneous Contrast

14. Are the dogs different colors?

15. Same dogs as last slide

16. Light and Shadow

17. Sensitivity to Detail

18. Shape from Shading

19. Showing Small Colored Objects on Large Colored Background GoodBad

20. Color Coding - Categories Appears to be a shared naming system across cultures and languages Can reliably use at most a dozen codes

21. Color Maps “Rainbow color map (still) considered harmful” http://eagereyes.org/basics/rainbow-color-map http://www.sandia.gov/~kmorel/documents/Col orMaps/ColorMaps.pdf http://www.sandia.gov/~kmorel/documents/Col orMaps/ColorMaps.pdf http://stackoverflow.com/questions/7251872/is- there-a-better-color-scale-than-the-rainbow- colormap http://stackoverflow.com/questions/7251872/is- there-a-better-color-scale-than-the-rainbow- colormap http://www.research.ibm.com/people/l/lloydt/co lor/color.HTM http://www.research.ibm.com/people/l/lloydt/co lor/color.HTM

22. 3 Perceptual Dimensions of Color

23. Color Map Accessibility

24. Color Encodings RGB – red-green-blue – additive color model Cylindrical color models – HSL/HCL hue, saturation/chromaticity, luminance/lightness – HSB/HSV hue, saturation, brightness/value

25. RGB Color Model From Wikipedia:

26. Cylindrical Color Models

27. Try these! Color Brewer – http://colorbrewer2.org http://colorbrewer2.org MudCube – http://mudcu.be/sphere http://mudcu.be/sphere – Can simulate color blindness of different types

28. Preparation for Next Class Finish Lab 1 – You will receive instructions by Friday on how to turn in your assignment Read Munzner Chapter 2