[css-color-5] Added contrast-color() to the color type definition

Author: svgeesus

css-color-5/Overview.bs

@@ -14,7 +14,7 @@ Editor: Chris Lilley, W3C, https://svgees.us/, w3cid 1438
 Editor: Una Kravets, Google, https://una.im, w3cid 115525
 Editor: Lea Verou, Invited Expert, http://lea.verou.me/about, w3cid 52258
 Editor: Adam Argyle, Google, https://nerdy.dev, w3cid 112669
-Abstract: This module extends CSS Color [[css-color-4]] to add color modification functions, custom color spaces (ICC profiles), light-dark() and device-cmyk().
+Abstract: This module extends CSS Color [[css-color-4]] to add color modification functions, custom color spaces (ICC profiles), contrast-color(), light-dark() and device-cmyk().
 Repository: w3c/csswg-drafts
 WPT Path Prefix: css/css-color/
 WPT Display: open
@@ -150,7 +150,8 @@ Introduction {#intro}
 	Colors in CSS are represented by the <dfn export><<color>></dfn> type:
 
 	<pre class='prod'>
-	&lt;color> = <<color-base>> | currentColor | <<system-color>> | <<device-cmyk()>>  | <<light-dark()>>
+	&lt;color> = <<color-base>> | currentColor | <<system-color>> | 
+				<<contrast-color()>> | <<device-cmyk()>>  | <<light-dark()>>
 
 	<dfn>&lt;color-base></dfn> = <<hex-color>> | <<color-function>> | <<named-color>> | <<color-mix()>> | transparent
 	<dfn>&lt;color-function></dfn> = <<rgb()>> | <<rgba()>> |
@@ -167,6 +168,7 @@ Introduction {#intro}
 	* ''currentColor'' (which depends on the value of the 'color' property)
 	* a <<system-color>> (which depends on the color mode)
 	* <<light-dark()>> (which depends on the color mode)
+	* <<contrast-color()>> (which depends on the color mode)
 	* <<device-cmyk()>> (which has no colorimetric basis)
 
 	Nor are any of those values used inside <<color-mix()>>