[css-color-4] serializing color() with alpha

Author: svgeesus

css-color-4/Overview.bs

@@ -757,9 +757,10 @@ This section updates and replaces that part of CSS Object Model, section
 
 	The component values are serialized in base 10,
 	as <<number>>.
-	A single ASII space character " "
+	A single ASCII space character " "
 	must be used as the separator
-	between the component values.
+	between the component values,
+	and also between the colorspace name and the first color component.
 
 	Trailing fractional zeroes in any component values must be omitted;
 	if the fractional part consists of all zeroes,
@@ -768,13 +769,29 @@ This section updates and replaces that part of CSS Object Model, section
 	<div class="example" id="ex-color-serial">
 		<p>The serialized value of</p>
 		<pre class="lang-css"><span class="swatch" style="--color: rgba(99.56%, 6.09%, 57.02%, 0.93)"></span> color(dIsPlAy-P3  0.964  0.763  0.787)</pre>
-		<p>Is the string "color(display-p3 0.96 0.76 0.79)",
+		<p>is the string "color(display-p3 0.96 0.76 0.79)",
 		if two decimal places are retained.
 		Notice that 0.787 has rounded up to 0.79,
 		rather than being truncated to 0.78.
 		</p>
 	</div>
 
+	<div class="example" id="ex-color-swop-serial">
+		<p>The serialized value of the color in</p>
+		<pre class="lang-css">@color-profile --swop5c {
+			src: url('https://example.org/SWOP2006_Coated5v2.icc');
+		  }
+		  .header {
+			background-color:  <span class="swatch" style="--color: rgb(94.903% 45.248% 59.104%)"></span>  color(--swop5c  0% 70.0% 20.00% .0%);
+		  }</pre>
+		<p>is the string "color(--swop5c 0 0.7 0.2 0)"</p>
+	</div>
+
+	<!--
+		the name in the @color-profile is also lowercased, right?
+		the serialization is not sufficient because the name and the link to the profile are also needed.
+	-->
+
 	If the colorspace is sRGB, the colorspace must be omitted in the serialized result.
 	<!--
 		could go either way on that but we need to pick one, and this is shorter
@@ -791,6 +808,23 @@ This section updates and replaces that part of CSS Object Model, section
 	(16bit, or half float, is recommended for internal storage).
 	Values must be rounded, not truncated.
 
+	<a href="#serializing-alpha-values">As noted earlier</a>,
+	unitary alpha values are not explicitly serialized.
+	Non-unitary alpha values must be explicitly serialized,
+	and the string " / "
+	(an ASCII space, then forward slash, then another space)
+	must be used to separate
+	the final color component value
+	from the alpha value.
+
+	<div class="example" id="ex-color-prophoto-alpha-serial">
+		<p>The serialized value of</p>
+		<pre class="lang-css"><span class="swatch" style="--color: rgba(0.003%, 50.196%, 50.196%, 0.85)"></span> color(prophoto-rgb 0.2804 0.40283 0.42259/85%)</pre>
+		<p>is the string "color(prophoto-rgb 0.28 0.403 0.423 / 0.85%)",
+		if three decimal places are retained.
+		</p>
+	</div>
+
 <h2 id='numeric-srgb'>
 sRGB Colors</h2>