[css-color] Reformat the predefined colorspace section, and add srgb per resolution.

Author: tabatkins

css-color/Overview.bs

@@ -1788,51 +1788,70 @@ Profiled, Device-dependent Colors</h2>
 	identical to ''rgb(0 0 0)''.
 
 <h3 id="predefined">
-Predefined colorspaces: ''dci-p3'' and ''rec2020''.</h3>
+Predefined colorspaces: ''srgb'', ''dci-p3'', and ''rec2020''.</h3>
 
-	These two colorspaces are indicated by using the predefined identifiers
-	''dci-p3'' or ''rec2020'' in the color function.
-	No ''@color-profile'' at-rule is needed for these predefined names;
-	if one is supplied, it will be ignored.
+	The following colorspaces are predefined for use in the ''color()'' function.
+	They can be used without any ''@color-profile'' rule.
 
 	Issue: Decided at San Francisco to add a larger set of common predefined spaces
 	like AdobeRGB, ProPhoto RGB, and so on. Also coated and uncoated swop, etc, etc.
 
-	The <dfn value for="color()">dci-p3</dfn> [[!DCI-P3]] colorspace has the following characteristics:
-
-	<table>
-		<tr><th>Red chromaticity</th><td>x=0.680 y=0.320</td></tr>
-		<tr><th>Green chromaticity</th><td>x=0.265 y=0.690</td></tr>
-		<tr><th>Blue chromaticity</th><td>x=0.150 y=0.060</td></tr>
-		<tr><th>White chromaticity</th><td>x=0.3127 y=0.3290 (D65)</td></tr>
-		<tr><th>Transfer function</th><td>1/2.6</td></tr>
-	</table>
-
-	Issue: The defining spec for dci-p3 is not freely available. It costs USD 240.
-		There is a Wikipedia article, which is non-authoritative and of unknown accuracy
-		(particularly for the transfer function and viewing conditions).
-
-	Issue: DCI transfer function for P3 is gamma 1/2.6 while Apple P3 displays use gamma 1/2.2.
-
-	The <dfn value for="color()">rec2020</dfn> [[!Rec.2020]] colorspace has the following characteristics:
-
-	<table>
-		<tr><th>Red chromaticity</th><td>x=0.708 y=0.292</td></tr>
-		<tr><th>Green chromaticity</th><td>x=0.170 y=0.797</td></tr>
-		<tr><th>Blue chromaticity</th><td>x=0.131 y=0.046</td></tr>
-		<tr><th>White chromaticity</th><td>x=0.3127 y=0.3290 (D65)</td></tr>
-		<tr><th>Transfer function</th><td>see below</td></tr>
-	</table>
-
-	''rec2020'' transfer function has the same form as the one for sRGB, but with
-	the constants at higher precision to cope with 10 or 12-bit components:
+	<dl dfn-type=value dfn-for="color()">
+		<dt><dfn>srgb</dfn>
+		<dd>
+			The ''srgb'' [[!DCI-P3]] colorspace accepts three numeric parameters,
+			representing the red, green, and blue channels of the color,
+			with each having a valid range of [0, 1].
 
-	<pre class="lang-javascript">
-	E < β ? 4.5 * E : α * Math.pow(E, 0.45) - (α - 1);
-	</pre>
+			It is the default colorspace for CSS,
+			identical to specifying a color with the ''rgb()'' function.
 
-	Where α=1.09929682680944  and β=0.018053968510807
-	<!-- full-precision constants here, not the rounded ones for 10 or 12bit components -->.
+		<dt><dfn>dci-p3</dfn>
+		<dd>
+			The ''dci-p3'' [[!DCI-P3]] colorspace accepts three numeric parameters,
+			representing the red, green, and blue channels of the color,
+			with each having a valid range of [0, 1].
+
+			It has the following characteristics:
+
+			<table>
+				<tr><th>Red chromaticity</th><td>x=0.680 y=0.320</td></tr>
+				<tr><th>Green chromaticity</th><td>x=0.265 y=0.690</td></tr>
+				<tr><th>Blue chromaticity</th><td>x=0.150 y=0.060</td></tr>
+				<tr><th>White chromaticity</th><td>x=0.3127 y=0.3290 (D65)</td></tr>
+				<tr><th>Transfer function</th><td>1/2.6</td></tr>
+			</table>
+
+			Issue: The defining spec for dci-p3 is not freely available. It costs USD 240.
+				There is a Wikipedia article, which is non-authoritative and of unknown accuracy
+				(particularly for the transfer function and viewing conditions).
+
+			Issue: DCI transfer function for P3 is gamma 1/2.6 while Apple P3 displays use gamma 1/2.2.
+
+		<dt><dfn>rec2020</dfn>
+			The ''rec2020'' [[!Rec.2020]] colorspace accepts three numeric parameters,
+			representing the red, green, and blue channels of the color,
+			with each having a valid range of [0, 1].
+
+			It has the following characteristics:
+
+			<table>
+				<tr><th>Red chromaticity</th><td>x=0.708 y=0.292</td></tr>
+				<tr><th>Green chromaticity</th><td>x=0.170 y=0.797</td></tr>
+				<tr><th>Blue chromaticity</th><td>x=0.131 y=0.046</td></tr>
+				<tr><th>White chromaticity</th><td>x=0.3127 y=0.3290 (D65)</td></tr>
+				<tr><th>Transfer function</th><td>see below</td></tr>
+			</table>
+
+			''rec2020'' transfer function has the same form as the one for sRGB, but with
+			the constants at higher precision to cope with 10 or 12-bit components:
+
+			<pre class="lang-javascript">
+			E < β ? 4.5 * E : α * Math.pow(E, 0.45) - (α - 1);
+			</pre>
+
+			Where α=1.09929682680944  and β=0.018053968510807
+			<!-- full-precision constants here, not the rounded ones for 10 or 12bit components -->.
 
 <h4 id="predefined-to-lab">
 Converting predefined colorspaces to Lab</h4>