Fix w3c#2678

Author: svgeesus

css-fonts-4/Overview.bs

@@ -3622,7 +3622,7 @@ Using these rules, the non-negative integers prefixed with "color-" are valid id
 
 Integers greater than 65534 in a color-<<integer>> descriptor are invalid.
 
-These descriptors are zero-indexed, so the initial palette in the font is represented by the <code>color-0</code> descriptor.
+These descriptors are zero-indexed, so the color specified by the first color record in the selected palette is overidden by the  <code>color-0</code> descriptor.
 
 Using CSS Variables is explicitly expected to be valid in the value of this descriptor.
 Using CSS Variables is disallowed in the key of this descriptor.