Template:Color contrast ratio/doc
Lua error: Cannot create process: proc_open(/log/lua.error): Failed to open stream: No such file or directory
Lua error: Cannot create process: proc_open(/log/lua.error): Failed to open stream: No such file or directory
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. |
|---|---|---|---|---|---|
| Template:Color sample #000000 | Template:Color sample #FFFFFF | Sample | {{Color contrast ratio|#000000|#FFFFFF}} | Expression error: Unexpected < operator. | AAA |
| Template:Color sample #000080 | Template:Color sample #DDDDDD | Sample | {{Color contrast ratio|#000080|#DDDDDD}} | Expression error: Unexpected < operator. | AAA |
| Template:Color sample #7B0000 | Template:Color sample #FF9900 | Sample | {{Color contrast ratio|#7B0000|#FF9900}} | Expression error: Unexpected < operator. | AA |
| Template:Color sample #004800 | Template:Color sample #AAAAAA | Sample | {{Color contrast ratio|#004800|#AAAAAA}} | Expression error: Unexpected < operator. | AA |
| Template:Color sample red | Template:Color sample white | Sample | {{Color contrast ratio|red|white}} | Expression error: Unexpected < operator. | No |
| Template:Color sample #FF0000 | Template:Color sample #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. |
|---|---|---|---|---|---|
| Template:Color sample #BADFEE | Template:Color sample black | Sample | {{Color contrast ratio|#BaDFeE|BlAcK}} | Expression error: Unexpected < operator. | AAA |
| Template:Color sample red | Template:Color sample black | Sample | {{Color contrast ratio|red|black}} | Expression error: Unexpected < operator. | AA |
| Template:Color sample #FFFF00 | Template:Color sample #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.