[css-color-5] Ported definitions for colors that "resolve to sRGB" and "support legacy color syntax" from CSS Color 4

Author: svgeesus

css-color-4/Overview.bs

@@ -877,7 +877,7 @@ Representing Colors: the <<color>> type</h2>
 	* the constant [=named color=] keywords
 	* the variable <<system-color>> keywords and ''currentColor'' keyword.
 
-	The <dfn>color functions</dfn>
+	The <dfn export>color functions</dfn>
 	use CSS [=functional notation=]
 	to represent colors in a variety of [=color spaces=]
 	by specifying their component coordinates.
@@ -960,7 +960,7 @@ Representing Colors: the <<color>> type</h2>
 		&lt;color> = <<color-base>> | currentColor | <<system-color>>
 
 		<dfn>&lt;color-base></dfn> = <<hex-color>> | <<color-function>> | <<named-color>> | transparent
-		<dfn>&lt;color-function></dfn> = <<rgb()>> | <<rgba()>> |
+		<dfn export>&lt;color-function></dfn> = <<rgb()>> | <<rgba()>> |
 									<<hsl()>> | <<hsla()>> | <<hwb()>> |
 									<<lab()>> | <<lch()>> | <<oklab()>> | <<oklch()>> |
 									<<color()>>

css-color-5/Overview.bs

@@ -145,6 +145,23 @@ Introduction {#intro}
 	Nor are any of those values used inside <<color-mix()>>
 	or in relative color syntax.
 
+	The colors that <dfn export>resolve to sRGB</dfn> are:
+
+	- <a href="css-color-4#hex-notation">hex</a> colors
+	- ''rgb()'' and ''rgba()'' values, including relative colors
+	- ''hsl()'' and ''hsla()'' values, including relative colors
+	- ''hwb()'' values, including relative colors
+	- <a href="css-color-4#named-colors">named</a> colors
+
+	The functions that <dfn export>support legacy color syntax</dfn> are:
+
+	- ''rgb()'' and ''rgba()''
+	- ''hsl()'' and ''hsla()''
+	
+	The <<hsl()>>, <<hsla()>>, <<hwb()>>, <<lch()>>, and <<oklch()>> [=color functions=]
+	are [=cylindrical polar color=] representations using a <<hue>> angle;
+	the other [=color functions=] use [=rectangular orthogonal color=] representations.
+
 
 
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