[css-color-4] Fix typo in example, fix w3c#7060

Author: svgeesus

css-color-4/Overview.bs

@@ -668,9 +668,9 @@ any achromatic color will have a [=powerless=] hue component.
 		to achieve an effect where you only <em>want</em> to interpolate certain components of a color.
 
 		For example, to animate a color to "grayscale", no matter what the color is,
-		one can interpolate it with ''lch(none 0% none)''.
+		one can interpolate it with ''lch(none 0 none)''.
 		This will take the hue and lightness from the starting color,
-		but animate its chroma down to 0%,
+		but animate its chroma down to 0,
 		rendering it into an equal-lightness gray
 		with a steady hue across the whole animation.