[css-color-5][editorial] typo

Author: Chris Lilley

css-color-5/Overview.bs

@@ -387,7 +387,7 @@ must not be omitted.
 		<span class="swatch" style="--color: rgba(25%, 75%, 0%, 0.325)"></span>
 		color(srgb 0.25 0.75 0 / 0.325)
 
-	This is a <em>huge</em> difference; the ΔE200 between the correct and incorrect results is 30.7!
+	This is a <em>huge</em> difference; the ΔE2000 between the correct and incorrect results is 30.7!
 </div>
 
 When the percentage ormalization gnerates an alpha multiplier,