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Re: trying a second time looking for color contrast rules


From: Bim Egan
Date: Aug 25, 2014 9:24PM

Hi Lucy,

WCAG 2.0 Success Criterion 1.4.3 Contrast (Minimum) requires a contrast
ratio of at least 4.5:1, for "normal" sized text or images of text.
For "large" text, (or images of large text), the minimum contrast ratio
is 3:1.
Large or larger scale text is defined as 18pt at normal font weight or
14pt for bold font weight.
There are exceptions, where no contrast minimum is required, these
include: inactive user interface controls, images of text where the text
is pure decoration and text in logos.
1.4.3 is a Level double-A requirement. The full description of this
success criterion is easiest to find immediately below the H1 in the
Understanding document at:

The triple-A Success Criterion is 1.4.6 (Contrast Enhanced). This
requires a minimum contrast ratio of 7:1 for "normal" sized text or
images of text and a contrast ratio of 4.5:1 for "large" or larger scale
text or images of text. The size definitions and the exceptions are
the same as in 1.4.3.
The Understanding document for 1.4.6 is at:

For guidance on relative sizing equivalents the above documents say
that 18pt is roughly 1.5em or 150% of the body text when the body text
is 1em or 100%. 14pt bold is roughly equivalent to 1.2em bold or 120%
bold where body text is 1em or 100%.



On 25/08/2014 23:29, Lucy Greco wrote:
> hello:
> sorry about my last message.I have recently switch my mail and have not
> worked out all the kinks yet.
> I am writing a short artacle about color contrast and was hoping some one
> could send me a plain text vertion of what the rules and percentages are
> for color contrast in W3C2.0 i normaly get a sited person to check these
> and don't really know what the percentages should be in all situations
> thanks lucy Lucia Greco
> Web Accessibility Evangelist
> IST - Architecture, Platforms, and Integration
> University of California, Berkeley
> (510) 289-6008 skype: lucia1-greco
> http://webaccess.berkeley.edu
> Follow me on twitter @accessaces
> > > >