[css-color-4] redo calc in example

Author: svgeesus

css-color-4/Overview.bs

@@ -4484,11 +4484,10 @@ Interpolating with alpha</h3>
 
 		The midpoint of linearly interpolating these,
 		along the shorter hue arc (the default) would be
-		[29.4365% 40.563 63.64]
+		[29.4365% 40.563 31.82]
 		which, with an alpha value of 0.5,
-		is  lch(58.873% 81.126 127.28) / 0.5)
-		when premultiplication is undone. This is within the display-p3 gamut, at color(display-p3 0.3535 0.6271 0.1369 / 0.5) but outside sRGB; the closest in-gamut color is
-		<span class="swatch oog" style="--color: rgb(87.604%, 38.956%, 51.753%, 0.5)"></span> rgb(23.92% 63.55% 0% / 0.5)
+		is <span class="swatch" style="--color: rgb(83.918% 44.583% 0% / 0.5)"></span>  lch(58.873% 81.126 63.64) / 0.5)
+		when premultiplication is undone.
 
 	</div>
 

css-color-4/style.css

@@ -10,6 +10,10 @@
 	box-shadow: 1px 1px 1px rgba(0,0,0,.15)
 }
 
+.swatch.oog {
+	border: 2px solid red;
+}
+
 .swatch:hover {
 	transform: scale(3);
 	border-radius: 2px;