[css-color-5] fix typo (w3c#10086)

* [css-color-5] fix typo

* [css-color-5] fix incorrect syntax

Author: romainmenke

css-color-5/Overview.bs

@@ -961,7 +961,7 @@ if the destination color space is capable of representing them.
 
 	<pre highlight=css>
 		--vivid-yellow: <span class="swatch oog" style="--color: color(display-p3 1 1 0)"></span> color(display-p3 1 1 0); 
-		--paler-yellow: <span class="swatch" style="--color: rgb(100% 100% 15.37%)"></span> srgb(from var(--vivid-yellow) r g calc(b + 50%));
+		--paler-yellow: <span class="swatch" style="--color: rgb(100% 100% 15.37%)"></span> color(from var(--vivid-yellow) srgb r g calc(b + 0.5));
 	</pre>
 
 	Here --vivid-yellow, once converted to sRGB, 
@@ -979,7 +979,7 @@ alpha channels <em>are</em> clamped to the reference range.
 	results in an alpha in the result of 1, not 1.4.
 
 	<pre highlight=css>
-		--tan: <span class="swatch" style="--color: rgb(80.93% 70% 55.27% / 70%)"></span> oklch(78% 0.06 75) / 0.7;
+		--tan: <span class="swatch" style="--color: rgb(80.93% 70% 55.27% / 70%)"></span> oklch(78% 0.06 75 / 0.7);
 		--deeper-tan: <span class="swatch" style="--color: rgb(80.93% 70% 55.27%)"></span> oklch(from var(--tan) l c h / calc(alpha * 2));
 	</pre>
 </div>