[css-color-4] Update changes section

Author: svgeesus

css-color-4/Overview.bs

@@ -4162,6 +4162,35 @@ Changes</h2>
 5 November 2019</a></h3>
 
 <ul>
+	<!-- changes to Oct 21 -->
+	<li>Added explanatory note on history and reason for standardizing X11 colors</li>
+	<li>Correct hwb sample code</li>
+	<li>Add table of DeltaE2000 values for MacBeth patches</li>
+	<li>Add note on ICC profe Internet Media type</li>
+	<li>Add reference to PNG sRGB chunk</li>
+	<li>Clarify CMYK to Lab interconversion</li>
+	<li>Clarify RGB to Lab interconversion</li>
+	<li>More comparison of HSL vs. LCH</li>
+	<li>More descripton for Rec BT.2020 colorspace</li>
+	<li>Updated description of prophoto-rgb</li>
+	<li>Removed duplicate "keywords" from Value Definitions section </li>
+	<li>Added an example of an invalid color</li>
+	<li>Added example with multiple fallbacks</li>
+	<li>Assorted typos and markup fixes</li>
+	<li>Clarify handling for undeclared custom colorspaces</li>
+	<li>Clarify some examples and explanatory notes</li>
+	<li>Handling for valid and invalid ICC profiles</li>
+	<li>Define handling for images with explicit tagged colorspace</li>
+	<li>Define clorspace for 4k, SDR video</li>
+	<li>State that user contrast settings mst take precedence</li>
+	<li>Clarify meaning of system colors outside for forced-color mode</li>
+	<li>Update default style rules</li>
+	<li>Add CIE XYZ colorspace to ''color()''</li>
+	<li>Greater clarity on hue angles, NaN explicitly allowed</li>
+	<li>Improve section on system clor pairings, require AA accessible contrast</li>
+	<li>Warn of interaction between overlapping glyphs and the opacity property</li>
+	<li>Correct grammar in color definition</li>
+	<li>Improve description of Highlight/HighlightText</li>
 	<li>Correct prophoto-rgb transfer function</li>
 	<li>More precision for prophoto-rgb primaries</li>
 	<li>Started to define "can't be displayed"</li>
@@ -4274,6 +4303,8 @@ Changes from Colors 3</h3>
 
 		<li>''device-cmyk()'' function, for specifying uncalibrated colors in an output-device-specific CMYK colorspace.
 
+		<li>Serialization of <<color>> now specified here, rather than in CSS Object Model
+
 		<li>Addition of named color ''rebeccapurple''.
 	</ol>