[css-color-4] Display as black or whete when L=0% or 100% is due to g…

…amut mapping #8794

css-color-4/Overview.bs

@@ -3179,8 +3179,9 @@ Specifying Lab and LCH: the ''lab()'' and ''lch()'' functional notations</h3>
 
 	If the lightness of a Lab color (after clamping) is ''0%'',
 	or ''100%''
-	both the a and b components are ''0''
-	and the color represents black, or white, respectively.
+	both the a and b components become powerless
+	and the color will be displayed as black, or white, respectively
+	due to gamut mapping to the display.
 
 	<div class="example" id="ex-lab-samples">
 		<pre class="lang-css">
@@ -3261,7 +3262,8 @@ Specifying Lab and LCH: the ''lab()'' and ''lch()'' functional notations</h3>
 	If the lightness of an LCH color (after clamping) is ''0%'',
 	or ''100%'', 
 	the hue component is [=powerless=]
-	and the chroma is ''0''.
+	and the color will be displayed as black, or white, respectively
+	due to gamut mapping to the display.
 
 	<div class="example" id="ex-lch-samples">
 		<pre class="lang-css">
@@ -3345,8 +3347,9 @@ Specifying Lab and LCH: the ''lab()'' and ''lch()'' functional notations</h3>
 
 	If the lightness of an Oklab color is ''0%'' or 0,
 	or ''100%'' or 1.0,
-	both the a and b components are 0
-	and the color represents black, or white, respectively.
+	both the a and b components become powerless
+	and the color will be displayed as black, or white, respectively
+	due to gamut mapping to the display.
 
 	<div class="example" id="ex-oklab-samples">
 		<pre class="lang-css">
@@ -3425,7 +3428,8 @@ Specifying Lab and LCH: the ''lab()'' and ''lch()'' functional notations</h3>
 		If the lightness of an Oklch color is ''0%'' or 0,
 		or ''100%'' or 1.0,
 		the hue component is [=powerless=]
-		and the chroma is ''0''.
+		and the color will be displayed as black, or white, respectively
+		due to gamut mapping to the display.
 
 		<div class="example" id="ex-oklch-samples">
 			<pre class="lang-css">