[css-color-4] remove all mention of Adobe® RGB (1998). w3c#6088

Author: svgeesus

css-color-4/Overview.bs

@@ -462,11 +462,11 @@ Accessibility and Conveying Information By Color</h3>
 
 	For example, when a browser running on a system with a Display P3 monitor
 	displays an JPEG image
-	tagged as being in the Adobe® RGB (1998) [[!AdobeRGB]]
+	tagged as being in the ITU Rec BT.2020 [[!Rec.2020]]
 	colorspace, it must convert the colors
-	from Adobe® RGB (1998) to Display P3
+	from ITU Rec BT.2020 to Display P3
 	so that they display correctly.
-	It must not treat the Adobe® RGB (1998) values
+	It must not treat the ITU Rec BT.2020 values
 	as if they were Display P3 values, which would produce incorrect colors.
 
 <h3 id='untagged'>
@@ -3448,17 +3448,6 @@ Predefined colorspaces: ''srgb'', ''display-p3'', ''a98-rgb'', ''prophoto-rgb'',
 			with each having a valid range of [0, 1]. The transfer curve is
 			a gamma function, close to but not exactly 1/2.2.
 
-			''a98-rgb'' is compatible with Adobe® RGB (1998) [[!AdobeRGB]].
-
-			Adobe® RGB (1998) uses primaries originally derived
-			from the SMPTE 240M standard;
-			errors in the original conversion turned out
-			to produce a colorspace that was useful for digital photography,
-			so Adobe® RGB (1998) is a common wider-gamut colorspace for
-			photographic images. The ''a98-rgb'' colorspace allows CSS to
-			specify colors that will match colors in such images
-			having the same RGB values.
-
 			It has the following characteristics:
 
 			<table>