[css-fonts-4] Clarify that non-absolute colors in override-colors make the whole descriptor invalid, not just the individual color #9555

Author: svgeesus

css-fonts-4/Overview.bs

@@ -7901,19 +7901,20 @@ Overriding a colors from a palette: The 'override-colors!!descriptor' descriptor
 	This descriptor overrides colors
 	to the initial color palette represented by this ''@font-palette-values'' rule.
 
-	The specified <<color>> must be an
-	[=absolute color=],
-	otherwise it is invalid.
-
 	The '@font-palette-values/override-colors' descriptor takes
 	a comma-separated list of palette index entries and colors.
 	Each item in the comma-separated list represents a tuple of
 	an entry into the palette and a color to replace it with.
 
+	Each specified <<color>> must be an
+	[=absolute color=],
+	otherwise the descriptor is invalid.
+
 	For each key/value pair in the value of this descriptor,
 	the color with that key in the initial palette (i.e. by using the 'base-palette' descriptor)
 	is overwritten by the color specified in this descriptor's value.
-	A key that is outside the range of indices of the initial palette is ignored.
+	A key that is outside the range of indices of the initial palette is ignored,
+	but does not make the descriptor invalid.
 
 	Palette index entries
 	in the ''@font-palette-values/override-colors'' descriptor