[css-fonts-4] correct CSSFontPaletteValuesRule interface, w3c#1655

Author: svgeesus

css-fonts-4/Overview.bs

@@ -4919,12 +4919,12 @@ The <code id="cssfontpalettevaluesrule2">CSSFontPaletteValuesRule</code> interfa
 };
 
 interface CSSFontPaletteValuesRule : CSSRule {
-  maplike&lt;unsigned long, (CSSOMString or CSSOMRGBColor)>;
+  maplike&lt;unsigned long, CSSOMString>;
   attribute CSSOMString fontFamily;
   attribute CSSOMString basePalette;
 };</pre>
 
-If the value of the 'setlike' functions is a CSSOMString, it is parsed as a solid color (e.g. using the <code>rgb()</code> syntax). If it refers to anything other than a solid color, the call is ignored or returns <code>undefined</code>.
+The value of the 'maplike' function [=CSS/parses=] as a <<color>>.
 
 The <code>fontFamily</code> and <code>basePalette</code> interfaces are parsed according to the appropriate CSS property syntax.