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Skabelon:Color contrast ratio/doc

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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).

Examples with light background

[rediger kildetekst]
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 Nej
#FF0000 #FF9999   Sample   {{Color contrast ratio|#FF0000|#FF9999}} 1.955 Nej

Examples with dark background

[rediger kildetekst]
Text
Color
Background
color
Sample Code Contrast
ratio
WCAG 2.0
conf.
#BADFEE black   Sample   {{Color contrast ratio|#BaDFeE|BlAcK}} 14.878 AAA
red black   Sample   {{Color contrast ratio|red|black}} 5.252 AA
#FFFF00 #00FFFF   Sample   {{Color contrast ratio|#FFFF00|#00FFFF}} 1.168 Nej

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.