Difference between revisions of "Template:Color contrast ratio"
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imported>AlanM1 m (AlanM1 moved page User:AlanM1/Template/Color contrast ratio to Template:Color contrast ratio: New template) |
imported>AlanM1 (Mod to allow HTML colors (and CSS "orange") in addition to RGB hex colors) |
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| − | <includeonly>{{#expr:({{RGBColorToLum|{{{2}}}}} + 0.05) / ({{RGBColorToLum|{{{1}}}}} + 0.05)}}</includeonly><noinclude>{{Documentation}}</noinclude> | + | <includeonly>{{#expr:({{#ifeq:{{Str left|{{{2}}}|1}}|#|{{RGBColorToLum|{{{2}}}}}|{{ColorToLum|{{{2}}}}}}} + 0.05) / ({{#ifeq:{{Str left|{{{1}}}|1}}|#|{{RGBColorToLum|{{{1}}}}}|{{ColorToLum|{{{1}}}}}}} + 0.05)}}</includeonly><noinclude>{{Documentation}}</noinclude> |
Revision as of 00:10, 2 March 2013
| This template uses Lua: |
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).
Contents
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}} | Expression error: Unexpected < operator. | AAA |
| #000080 | #DDDDDD | Sample | {{Color contrast ratio|#000080|#DDDDDD}} | Expression error: Unexpected < operator. | AAA |
| #7B0000 | #FF9900 | Sample | {{Color contrast ratio|#7B0000|#FF9900}} | Expression error: Unexpected < operator. | AA |
| #004800 | #AAAAAA | Sample | {{Color contrast ratio|#004800|#AAAAAA}} | Expression error: Unexpected < operator. | AA |
| red | white | Sample | {{Color contrast ratio|red|white}} | 3.998 | No |
| #FF0000 | #FF9999 | Sample | {{Color contrast ratio|#FF0000|#FF9999}} | Expression error: Unexpected < operator. | No |
Examples with dark background
| Text Color |
Background color |
Sample | Code | Contrast ratio |
WCAG 2.0 conf. |
|---|---|---|---|---|---|
| #BADFEE | black | Sample | {{Color contrast ratio|#BaDFeE|BlAcK}} | Expression error: Unexpected < operator. | AAA |
| red | black | Sample | {{Color contrast ratio|red|black}} | 0.19 | AA |
| #FFFF00 | #00FFFF | Sample | {{Color contrast ratio|#FFFF00|#00FFFF}} | Expression error: Unexpected < operator. | 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:
| 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
- Template:Color contrast conformance
- Wikipedia:WikiProject Accessibility
- Colour Contrast Check
- G18: Ensuring that a contrast ratio of at least 4.5:1 exists between text (and images of text) and background behind the text
- Index of Color Contrast Samples
| The above documentation is transcluded from Template:Color contrast ratio/doc. (edit | history) Editors can experiment in this template's sandbox (edit | diff) and testcases (create) pages. Please add categories to the /doc subpage. Subpages of this template. |