[css-color-4][edtorial] Add wpt, cleanup markup

Author: svgeesus

css-color-4/Overview.bs

@@ -6008,6 +6008,7 @@ Sample Pseudocode for the Binary Search Gamut Mapping with Local MINDE</h4>
 	</li>
 	<li>return |clipped| as the gamut mapped color</li>
 </ol>
+</div>
 
 <h4 id="GMA-EdgeSeeker">
 	The EdgeSeeker Gamut Mapping
@@ -7789,6 +7790,9 @@ relative-currentcolor-rgb-02.html
 relative-currentcolor-xyzd50-01.html
 relative-currentcolor-xyzd65-01.html
 relative-color-with-zoom.html
+parsing/alpha-color-computed.html
+parsing/alpha-color-parsing-invalid.html
+parsing/alpha-color-parsing-valid.html
 
 parsing/color-mix-out-of-gamut.html
 parsing/color-invalid.html
@@ -7801,6 +7805,9 @@ parsing/color-valid-relative-color.html
 parsing/relative-color-out-of-gamut.html
 /css/css-color/color-mix-missing-components.html
 
+light-dark-image.html
+
+animation/contrast-color-interpolation.html
 color-layers-no-blend-mode.html
 parsing/color-invalid-color-layers-function.html
 parsing/color-valid-color-layers-function.html