[css-color-4][editorial] Update changes

Author: svgeesus

css-color-4/Overview.bs

@@ -8442,6 +8442,9 @@ Changes</h2>
 	<a href="https://www.w3.org/TR/2025/CRD-css-color-4-20250424/">Candidate Recommendation Draft of 24 April 2025</a></h3>
 
 <ul>
+	<li>Explained color difference metrics better, and added ΔΕOKr2
+		(<a href="https://github.com/w3c/csswg-drafts/issues/14207">Issue 14207</a>)
+	</li>
 	<li>Added Oklab a,b plane diagrams for the sRGB, display-p3, a98-rgb, prophoto-rgb,
 		and rec2020 predefined color spaces, alongside the existing CIE Lab diagrams
 	</li>