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2017 CSUN Color Contrast


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Color helps us distinguish objects from each other and guides our attention to and away from things. This presentation will help you understand the issues.

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2017 CSUN Color Contrast

  1. 1. © 2016 AT&T Intellectual Property. All rights reserved. AT&T, Globe logo, Mobilizing Your World and DIRECTV are registered trademarks and service marks of AT&T Intellectual Property and/or AT&T affiliated companies. All other marks are the property of their respective owners. March 1, 2017 Color Contrast A deep dive into our colorful world Crystal Baker Senior Accessibility Solutions Engineer AT&T Corporate Accessibility Technology Office (CATO)
  2. 2. POLL: Is the trashcan tan or grey? TAN GREY
  3. 3. 3 When we survey the characteristics of color effects, we can detect seven different kinds of contrast…Each unique in character and artistic value, in visual, expressive, and symbolic effect; and together they constitute the fundamental resource of color design. -Johannes Itten
  4. 4. 4 Itten’s Color Theory 1. Contrast of Hue 2. Light-Dark Contrast 3. Cold-Warm Contrast 4. Complementary Contrast 5. Simultaneous Contrast 6. Contrast of Saturation 7. Contrast of Extension
  5. 5. 5 Color Expression  Yellow – light giving  Red – fiery strength  Blue - passive  Green – fruitfulness  Orange - radiant  Violet - mysterious
  6. 6. 6 Fun Facts  99% of all colorblind people are not really color blind but color deficient; the term color blindness is misleading.  Color blindness is more prevalent among males than females.  “What color is this?” is the most annoying question you can ask your colorblind friend.  Ishihara plates are the best known color blindness tests, but they are not the most accurate ones.
  7. 7. How do we see color?  The human eye sees by light stimulating the retina, a lining inside the back of the eye. The retina is made up of what are called Rods and Cones.  The rods, located on the outer edge of the retina, give us our night vision but cannot distinguish color.  Cones, located in the center of the retina, are not much good at night but do let us perceive color during daylight conditions.  Color-detecting molecules, photopigments, are located in the cones. There are three different kinds of cones that respond to blue, green and red light.
  8. 8. 8 Three main types of colorblind categories: 1. Color Vision Deficiency:  deutan - Red, orange, yellow, green appear shifted in hue towards red  protan –Red, orange, yellow, and yellow-green appear shifted in hue towards green  tritan – Blue shifts toward green, and yellow shifts toward violet 2. Dichromasy – one cone isn’t functioning properly at all. They see no perceptible difference between red, orange, yellow, and green. 3. Monochromasy – total colorblindness, where the individual only sees black and white and the various shades of grey in between.
  9. 9. 9 Color Vision Deficiency Examples Normal Vision Deuteronopia Protanopia Tritanopia
  10. 10. 10 Fun Facts  The terms protan, deutan, and tritan are Greek and translate to first, second, and third.  A father can’t pass his red-green color blindness on to his sons.  If a woman is red-green colorblind, all her sons will also be colorblind.  Dogs are not colorblind.
  11. 11. 11 Can you just eyeball it?
  12. 12. 12 How to Use Contrast in Color  If you are not experienced in working with color, keep color schemes conservative, conventional, and simple.  Use subtle shades of natural colors.  Avoid bold, highly saturated primary colors except in areas of maximum emphasis, and even then, use caution.  Choose colors that reside on the same quadrant of the color wheel.  Type must always contrast sharply with background colors to be readable.
  13. 13. Testing Color Contrast  Colour Contrast Analyser by The Paciello Group  Color Contrast Checker by Web AIM 13
  14. 14. Tools  The tools help you determine the legibility of text and the contrast of visual elements, such as graphical controls and visual indicators.  The tools are a pass/fail assessment against WCAG 2.0 color contrast success criteria.  The tools are a simulation of certain visual conditions, including dichromatic color-blindness and cataracts, to demonstrate how your web content appears to people with less than 20/20 vision.  The tools are *FREE*.
  15. 15. Luminosity Contrast Ratio  (L1 + 0.05)/(L2 + 0.05)  L1 is the luminosity of the lighter of the text or background colors  L2 is the luminosity of the darker of the text or background colors.  Note 1: The luminosity of a color is defined as 0.2126 * ((R / FS) ^ 2.2) + 0.0722 * ((B /FS) ^ 2.2).  R, G, and B are the red, green, and blue RGB values of the color.  FS is the maximum possible full scale RGB value for R, G, and B (255 for 8 bit color channels).  The “^” character is the exponentiation operator.  Note 2: Luminosity values can range from 0 (black) to 1 (white), and luminosity contrast ratios can range from 1 to 21.
  16. 16. Fun Facts  Colorblind people feel disabled in everyday life, and almost nobody recognizes this.  John Dalton wrote the first known scientific paper regarding color blindness in 1794.  In certain countries you need normal color vision to get a drivers license.  The anomaloscope is the most accurate color blindness test known today.
  17. 17. Demo  Colour Contrast Analyzer  Color Contrast Checker
  18. 18. 18 Fun Facts  Red-green color blindness is a recessive sex linked trait, which causes more men to be colorblind than women.  Blue-yellow color blindness is a dominant, not sex linked, trait, which means both men and women are equally affected.  Many colorblind people have problems with matching clothes and buying ripe bananas.  There is no treatment or cure for color blindness.
  19. 19. POLL: Do logos have to meet color contrast ratios? YES NO
  20. 20. 20 Fun Facts  John Dalton believed his whole life that the cause of his color blindness is a colored fluid inside his eye balls.  Police officer, firefighter, and airline pilot are the most famous jobs requiring normal color vision.  Quite a lot of people with normal color vision can’t pass an Ishihara plates test free of errors.  The International Colour Vision Society is scientifically investigating every aspect of color vision and color vision deficiency.
  21. 21. s blue and blac k or whit e and gold ?
  22. 22. Presentation Resources      color.html  
  23. 23. Tool Resources    to_improve_the_accessibility_of_your_design/
  24. 24. 25 Upcoming AT&T Presentations at CSUN WEDNESDAY 4:20PM AT&T Mobile and Desktop chat with ARIA: A Look Under the Hood Glenn Bradford - Gaslamp AB, 2nd Floor, Seaport Tower FRIDAY 9:00AM The Art of Language in Accessibility Crystal Baker - Balboa C, 2nd Floor, Seaport Tower 9:00AM The Ongoing Challenge: Mobile Accessibility Testing Jean Swart - La Jolla B, 2nd Floor, Seaport Tower 3:20PM A11y Lab: Conquering Mobile Accessibility though Device Analysis Cory Cain and Glenn Bradford - Balboa C, 2nd Floor, Seaport Tower