A presentation at UX/UI-Sprechstunde @ Tagesspiegel by Gunnar Bittersmann
COLOR CONTRAST
→ noti.st/cariefisher/Bin4xT
based on a drawing by Ramón y Cajal, 1911 by Anka Friedrich, vectorisation by chris 論, CC BY-SA 3.0
Diagram: cone types S, M, L x axis: Wavelength (nm) y axis: Normalized cone response (linear energy)
arithmetic mean L=(R+G+B)/3 L = 0.3333 R + 0.3333 G + 0.3333 B
weighted arithmetic mean L = 0.2126 R + 0.7152 G + 0.0722 B
relative luminance L = 0.2126 R + 0.7152 G + 0.0722 B
contrast ratio (L₁ + 0.05) / (L₂ + 0.05), where L₁ ≥ L₂
COLOR CONTRAST
WCAG, formulas, contrast-checking tools, accessibility evaluation browser plug-ins
The following resources were mentioned during the presentation or are useful additional information.
A presentation at axe-con by Carie Fisher
A presentation at A11y Meetup Berlin by Gunnar Bittersmann
Bruce Springsteen, from the album Born to Run
Bruce Springsteen Live at the Hammersmith Odeon, London 1975
Bruce Springsteen & The E Street Band Live In Barcelona
W3C WAI (Web Accessibility Initiative)
by Kezz Bracey
from deque
Web Accessibility Evaluation Tools from WebAIM
The following code examples from the presentation can be tried out live.
