[css-color-4] make color propdef match prose. fix w3c#1851

Author: svgeesus

css-color-4/Overview.bs

@@ -59,7 +59,7 @@ Foreground Color: the 'color' property</h2>
 	<pre class=propdef>
 	Name: color
 	Value: <<color>>
-	Initial: UA-defined, see prose
+	Initial: ''black''
 	Applies to: all elements
 	Inherited: yes
 	Percentages: N/A
@@ -70,8 +70,6 @@ Foreground Color: the 'color' property</h2>
 	This property describes the foreground fill color of an element's text content.
 	In addition, it provides the value that ''<color>/currentcolor'' resolves to.
 
-	The initial value of this property is ''black''.
-
 	There are several different ways to syntactically specify a given color.
 For example, to specify lime green:
 
@@ -3414,6 +3412,7 @@ Changes</h2>
 <h3 id="changes-from-20160705" class='no-num'>Changes since <a href="http://www.w3.org/TR/2016/WD-css-color-4-20160705/">Working Draft of 05 July 2016</a></h3>
 
 <ul>
+	<li>Initial value of the "color" property is now black</li>
 	<li>Clarify hue in LCH is modulo 360deg</li>
 	<li>Clarify allowed range of L in LCH and Lab, and meaning of L=100</li>
 	<li>Update references for colorspaces used in video</li>