[css-color-5] Non-RCS modern rgb & rgba also allows mixed num-pct w3c#8231

Author: Chris Lilley

css-color-4/Overview.bs

@@ -894,6 +894,7 @@ Modern (Space-separated) Color Function Syntax</h4>
 	* minimum required precision <a href="#serializing-color-values">when serializing</a> is defined,
 		and may be greater than 8 bits per component
 	* the ''none'' value is allowed, to represent [=missing components=]
+	* components using <<percentage>> and <<number>> may be freely mixed
 
 	<div class=example id="example-modern-syntax">
 		<p>The following represents a saturated sRGB red that is 50% opaque:
@@ -920,6 +921,8 @@ Legacy (Comma-separated) Color Function Syntax</h4>
 		(optionally preceded and/or followed by whitespace)
 	* minimum required precision is lower, 8 bits per component
 	* the ''none'' value is not allowed
+	* components must be specified using either all-<<percentage>>
+		or all-<<number>>, they can not be mixed.
 
 	<div class=example id="example-rgba-legacy">
 		<p>The following represents a saturated sRGB red that is 50% opaque:

css-color-5/Overview.bs

@@ -1003,17 +1003,16 @@ However, if calculations are done on missing values, ''none'' is treated as 0.
 
 <h3 id="relative-RGB">Relative sRGB Colors</h3>
 
-The grammar of the ''rgb()'' function is extended as follows:
+The grammar of the [=modern color syntax=] ''rgb()'' and ''rgba()'' functions are extended as follows:
 
 <pre class='prod'>
-	<dfn>rgb()</dfn> = rgb( [<<percentage>> | none]{3} [ / [<<alpha-value>> | none] ]? ) |
-				  rgb( [<<number>> | none]{3} [ / [<<alpha-value>> | none] ]? ) |
-				  rgb( [ from <<color>> ]? [ <<number>> | <<percentage>> | none]{3} [ / [<<alpha-value>> | none] ]?  )
+	<dfn>rgb()</dfn> = rgb( [ from <<color>> ]? [ <<number>> | <<percentage>> | none]{3} [ / [<<alpha-value>> | none] ]?  )
+	<dfn>rgba()</dfn> = rgba( [ from <<color>> ]? [ <<number>> | <<percentage>> | none]{3} [ / [<<alpha-value>> | none] ]?  )
 	<dfn>&lt;alpha-value></dfn> = <<number>> | <<percentage>>
 	</pre>
 
 
-Within a [=relative color=] syntax ''rgb()'' function,
+Within a [=relative color=] syntax ''rgb()'' or ''rgba()'' function,
 the allowed [=channel keywords=] are:
 
 * <dfn value for="rgb()">r</dfn>, <dfn value for="rgb()">g</dfn>, and <dfn value for="rgb()">b</dfn>