[css-color-4] update changes w3c#5922

Author: svgeesus

css-color-4/Overview.bs

@@ -4740,7 +4740,8 @@ Changes</h2>
 </h3>
 
 <ul>
-	<!-- to 29 jan 2021 -->
+	<!-- to 3 Feb 2021 -->
+	<li>Small correction to the sRGB to XYZ to sRGB matrices, improve round-tripping</li>
 	<li>Clarified the rec2020 transfer function, citing the correct ITU Rec BT.2020-2 reference</li>
 	<li>Correct fallback examples to use the correct syntax</li>
 	<li>Don't force non-legacy colors to interpolate in a gamma-encoded space</li>