What is CheckMyColours?
It is a tool for checking foreground and background color combinations of all DOM elements and determining if they provide sufficient contrast when viewed by someone having color deficits.
All the tests are based on the algorithms suggested by the World Wide Web Consortium (W3C).
Luminosity Constrast Ratio (WCAG 2.0)
(L1+.05) / (L2+.05) where L is luminosity and is defined as .2126*R + .7152*G + .0722B using linearised R, G, and B values. Linearised R (for example) = (R/FS)^2.2 where FS is full scale value (255 for 8 bit color channels). L1 is the higher value (of text or background) and L2 is the lower value.
Text or diagrams and their background must have a luminosity contrast ratio of at least 4.5:1 for level 2 conformance to guideline 1.4, and at least 7:1 for level 3 conformance to guideline 1.4.
Color brigthness (WCAG 1.0)
((Red value X 299) + (Green value X 587) + (Blue value X 114)) / 1000
The range for color brightness difference is 125.
The range for color difference is 500.
Recent News
September 2009 - CheckMyColours.com is now on Twitter
Three months after launch, we want to say thanks to everyone who appreciated the service and gave us important feedbacks.
New improvements and features coming soon, so...
stay tuned and follow us on twitter ;)
June 2009 - CheckMyColours.com is online!
This is a beta version. We hope that it will be useful for web developers.
We appreciate your feedback, so feel free to contact us for help or suggestions.
Mail to: info@checkmycolours.com
Sample
Text
Color Difference is
Luminosity Contrast Ratio is
More info on web accessibility: WAI - WCAG 1.0 - WCAG 2.0
© copyleft 2009 - 2010 - checkmycolours.com - Giovanni Scala