[css-color-5] channel keywords havea single type, same as css-color-4.

Author: Chris Lilley

css-color-5/Overview.bs

@@ -1436,8 +1436,8 @@ the number and name of the allowed [=channel keywords=] are:
 
 * defined by the '@color-profile/components' descriptor on the corresponding ''@color-profile'',
 	if present;
-	otherwise, no relative color manipulation is valid. They are <<number>>s or <<percentage>>s that correspond to the [=origin color's=] channels
-	after its conversion to the color space of the color profile. For <<number>>s, 1.0 corresponds to 100%.
+	otherwise, no relative color manipulation is valid. They are <<number>>s that correspond to the [=origin color's=] channels
+	after its conversion to the color space of the color profile. The value 1.0 corresponds to 100%.
 
 Within a [=relative color=] syntax ''color()'' function using <<predefined-rgb-params>>,
 the allowed [=channel keywords=] are: