[fonts-4] @font-palette-values uses illegal integer descriptor names

#1523

Author: Litherum

css-fonts-4/Overview.bs

@@ -3403,8 +3403,8 @@ The ''@font-palette-values'' rule accepts the descriptors defined in this specif
 	@font-palette-values Augusta {
 		font-family: Handover Sans;
 		base-palette: 3;
-		1: rgb(43, 12, 9);
-		3: var(--highlight);
+		color-1: rgb(43, 12, 9);
+		color-3: var(--highlight);
 	}
 	</pre>
 </div>
@@ -3501,10 +3501,10 @@ Colors can be added to the color palette
 by using the <<integer>> descriptor in the ''@font-palette-values'' rule.
 
 <h3 id="palette-integer-desc">
-Overriding a color in the palette: The <<integer>> descriptor</h3>
+Overriding a color in the palette: The 'color-<<integer>>' descriptors</h3>
 
 <pre class='descdef'>
-Name: <<integer>>
+Name: color-<<integer>>
 Value: <<color>>
 For: @font-palette-values
 Initial: N/A
@@ -3524,13 +3524,29 @@ Otherwise, a new color is added to this color palette at the index of this descr
 	<pre>
 	@font-palette-values Augusta {
 		font-family: Handover Sans;
-		1: rgb(43, 12, 9);
-		2: rgb(208, 112, 96);
-		3: var(--highlight);
+		color-1: rgb(43, 12, 9);
+		color-2: rgb(208, 112, 96);
+		color-3: var(--highlight);
 	}
 	</pre>
 </div>
 
+The parsing rules for these descriptors are as follows:
+
+1. The descriptor must start with the string "color-".
+
+2. If there is nothing remaining in the string, it is a parse failure.
+
+3. Otherwise, if the next character is a 0, the presence of anything after the 0 results in a parse failure.
+
+4. Otherwise, if the next character is a non-zero digit (1 through 9), the remainder of the string must be digits.
+
+5. Otherwise, it is a parse failure.
+
+Using these rules, the non-negative integers prefixed with "color-" are valid identifiers.
+
+These descriptors are zero-indexed, so the initial palette in the font is represented 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.
 CSS Variables are resolved in the context of the element to which the 'font-palette' property applies.