[css-color-4] update system color pairings, fix w3c#5639

Author: svgeesus

css-color-4/Overview.bs

@@ -1107,8 +1107,11 @@ System Colors</h3>
 
 	<ul id=system-color-pairs>
 		* ''Canvas'' background with ''CanvasText'', ''LinkText'', ''VisitedText'', ''ActiveText'' foreground.
+		* ''Canvas'' background with a ''ButtonBorder'' border and adjacent color ''Canvas''
 		* ''ButtonFace'' background with ''ButtonText'' foreground.
 		* ''Field'' background with ''FieldText'' foreground.
+		* ''Mark'' background with ''MarkText'' foreground
+		* ''ButtonFace'' or ''Field'' background with a ''ButtonBorder'' border and adjacent color ''Canvas'''
 		* ''Highlight'' background with ''HighlightText'' foreground.
 	</ul>
 
@@ -1124,10 +1127,14 @@ System Colors</h3>
 		<p>Canvas with VisitedText <span style="background-color:Canvas; color:VisitedText">VisitedText</span></p>
 		<p>Canvas with ActiveText <span style="background-color:Canvas; color:ActiveText">ActiveText</span></p>
 		<p>Canvas with GrayText <span style="background-color:Canvas; color:GrayText">GrayText</span></p>
+		<p>Canvas with ButtonBorder and adjacent Canvas <span style="background-color:Canvas; border: ButtonBorder; color:CanvasText; padding: 3px">CanvasText</span><span style="background-color:Canvas; color:CanvasText">Adjacent</span></p>
 		<p>ButtonFace with ButtonText <span style="background-color:ButtonFace; color:ButtonText">ButtonText</span></p>
+		<p>ButtonFace with ButtonText and ButtonBorder <span style="background-color:ButtonFace; color:ButtonText; border:ButtonBorder; padding: 3px">ButtonText</span></p>
 		<p>ButtonFace with GrayText <span style="background-color:ButtonFace; color:GrayText">GrayText</span></p>
 		<p>Field with FieldText <span style="background-color:Field; color:FieldText">FieldText</span></p>
 		<p>Field with GrayText <span style="background-color:Field; color:GrayText">GrayText</span></p>
+		<p>Mark with MarkText <span style="background-color:Mark; color:MarkText">FieldText</span></p>
+		<p>Mark with GrayText <span style="background-color:Mark; color:GrayText">GrayText</span></p>
 		<p>Highlight with HighlightText <span style="background-color:Highlight; color:HighlightText">HighlightText</span></p>
 		<p>Highlight with GrayText <span style="background-color:Highlight; color:GrayText">GrayText</span></p>
 	</div>