[css-color-4][editorial] Add gamut figure, update acks

Author: svgeesus

css-color-4/Overview.bs

@@ -409,6 +409,14 @@ Value Definitions</h3>
 	Devices with a limited gamut cannot produce very saturated colors,
 	like those found in a rainbow.
 
+	<figure id="fig-three-gamuts">
+		<p><img src="./images/sRGB-DisplayP3-rec2020-in-Oklab.png" alt=""></p>
+		<!-- alt text would be identical to figure caption -->
+		<figcaption>
+			A top-down view of three gamuts, plotted in Oklab with the positive a-axis towards the right and the positive b-axis towards the top; looking down the l-axis so white and neutrals are in the center. The largest of the three gamuts is ITU Rec BT.2020; the medium-sized one is Display P3, and the smallest is sRGB. Rendering by Alexey Ardov.
+		</figcaption>
+	</figure>
+
 	The gamuts of different [=color space=]s may be compared
 	by looking at the volume (in cubic Lab units) of colors that can be expressed.
 	The following table examines the <a href="#predefined">predefined</a> color spaces available in CSS.
@@ -6887,7 +6895,7 @@ Acknowledgments</h2>
 
 In addition to <a href="https://www.w3.org/TR/css-color-3/#acknowledgments">those
 who contributed to CSS Color 3</a>, the editors would like to thank
-Emilio Cobos Álvarez, Chris Bai, Amelia Bellamy-Royds, Lars Borg, Mike Bremford, Andreu Botella, Dan Burzo, Max Derhak, fantasai, Simon Fraser, Devon Govett, Phil Green, Dean Jackson, Andreas Kraushaar, Pierre-Anthony Lemieux, Cameron McCormack, Romain Menke, Chris Murphy, Isaac Muse, Jonathan Neal, Chris Needham, Christoph Päper, Brad Pettit, Xidorn Quan, Craig Revie, Melanie Richards, Florian Rivoal, Jacob Rus, Joseph Salowey, Simon Sapin, Igor Snitkin, Lea Verou, Mark Watson, Sam Weinig, and Natalie Weizenbaum.
+Emilio Cobos Álvarez, Alexey Ardov, Chris Bai, Amelia Bellamy-Royds, Lars Borg, Mike Bremford, Andreu Botella, Dan Burzo, Max Derhak, fantasai, Simon Fraser, Devon Govett, Phil Green, Dean Jackson, Andreas Kraushaar, Pierre-Anthony Lemieux, Tiaan Louw, Cameron McCormack, Romain Menke, Chris Murphy, Isaac Muse, Jonathan Neal, Chris Needham, Björn Ottosson, Christoph Päper, Brad Pettit, Xidorn Quan, Craig Revie, Melanie Richards, Florian Rivoal, Jacob Rus, Joseph Salowey, Simon Sapin, Igor Snitkin, Lea Verou, Mark Watson, James Stuckey Weber, Sam Weinig, and Natalie Weizenbaum.
 
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