Difference between revisions of "Template:Color contrast ratio/doc"

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imported>He7d3r
(+section for light-on-dark examples; +Index of Color Contrast Samples; +Ensuring that a contrast ratio of at least 4.5:1 exists between text (and images of text) and background behind the text)
imported>RexxS
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== WCAG 2.0 ==
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As a guide to selecting foreground and background colors for text, the [http://www.w3.org/TR/WCAG20/#visual-audio-contrast Web Content Accessibility Guidelines 2.0 (guideline 1.4)] classifies contrast ratios for ordinary text as follows:
 +
 +
{| class="wikitable"
 +
|+ WCAG 2.0 text contrast ratios
 +
|-
 +
! scope="col" | Font size
 +
! scope="col" | Not Compliant
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! scope="col" | Level AA
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! scope="col" | Level AAA
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|-
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| Normal
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| < 4.5
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| 4.5 to 7.0
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| > 7.0
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|-
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| Large (18&nbsp;pt or 14&nbsp;pt bold)
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| < 3.0
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| 3.0 to 4.5
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| > 4.5
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|}
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Normal wiki-text is rendered by common browsers at roughly 9.5 to 10.5&nbsp;pt (12.5 to 14&nbsp;px), depending on skin. Text would need to be about 180% or 140% bold to qualify as "Large" for [http://www.w3.org/TR/WCAG20/#larger-scaledef WCAG purposes].
  
 
== See also ==
 
== See also ==

Revision as of 13:22, 19 July 2014

This template returns the color contrast ratio between the two colors provided. It accepts two parameters, which can be a standard RGB hex color code (#RRGGBB) or a standard HTML color or CSS "orange" (= #FFA500). Color names and hex letters are case-insensitive (i.e. they may be upper- or lower-case).

Usage

Examples with light background

Text
Color
Background
color
Sample Code Contrast
ratio
WCAG 2.0
conf.
#000000 #FFFFFF   Sample   {{Color contrast ratio|#000000|#FFFFFF}} 21 AAA
#000080 #DDDDDD   Sample   {{Color contrast ratio|#000080|#DDDDDD}} 11.787 AAA
#7B0000 #FF9900   Sample   {{Color contrast ratio|#7B0000|#FF9900}} 5.324 AA
#004800 #AAAAAA   Sample   {{Color contrast ratio|#004800|#AAAAAA}} 4.691 AA
red white   Sample   {{Color contrast ratio|red|white}} 3.998 No
#FF0000 #FF9999   Sample   {{Color contrast ratio|#FF0000|#FF9999}} 1.955 No

Examples with dark background

Text
Color
Background
color
Sample Code Contrast
ratio
Reciprocal WCAG 2.0
conf.
#BADFEE black   Sample   {{Color contrast ratio|#BaDFeE|BlAcK}} 14.878 14.878 AAA
red black   Sample   {{Color contrast ratio|red|black}} 5.252 5.252 AA
#FFFF00 #00FFFF   Sample   {{Color contrast ratio|#FFFF00|#00FFFF}} 1.168 1.168 No

WCAG 2.0

As a guide to selecting foreground and background colors for text, the Web Content Accessibility Guidelines 2.0 (guideline 1.4) classifies contrast ratios for ordinary text as follows:

WCAG 2.0 text contrast ratios
Font size Not Compliant Level AA Level AAA
Normal < 4.5 4.5 to 7.0 > 7.0
Large (18 pt or 14 pt bold) < 3.0 3.0 to 4.5 > 4.5

Normal wiki-text is rendered by common browsers at roughly 9.5 to 10.5 pt (12.5 to 14 px), depending on skin. Text would need to be about 180% or 140% bold to qualify as "Large" for WCAG purposes.

See also