[css-pseudo-4] Clarify that fallback color of a highlight pseudo could come from ::first-line etc. w3c#4625

Author: fantasai

css-pseudo-4/Overview.bs

@@ -696,8 +696,9 @@ Painting the Highlight</h3>
   using its own 'color',
   with ''currentColor'' on its 'color' property representing the 'color'
   of the next <a>highlight pseudo-element</a> layer below,
-  falling back finally to that of the <a>originating element</a>
-  (the colors that would otherwise be used).
+  falling back finally to the colors that would otherwise have been used
+  (those applied by the [=originating element=] or
+  an intervening [=pseudo-element=] such as ''::first-line'' or ''::first-letter'').
   Any text decorations introduced by each <a>highlight pseudo-element</a>
   are stacked in the same order as their backgrounds
   over the text’s original decorations
@@ -980,6 +981,10 @@ Changes</h2>
     (<a href="https://github.com/w3c/csswg-drafts/issues/2998">Issue 2998</a>)
     <li>Allowed highlight overlay of inline-level boxes to extend to the line box edges.
     (<a href="https://github.com/w3c/csswg-drafts/issues/5395">Issue 5395</a>)
+    <li>Clarify that ''currentColor'' on a [=highlight pseudo-element=]
+    uses the color that would be used if the text were not “highlighted”,
+    even if that color was provided by a pseudo-element like ''::first-line''.
+    (<a href="https://github.com/w3c/csswg-drafts/issues/4625">Issue 4625</a>)
   </ul>
 
   Changes since the <a href="https://www.w3.org/TR/2016/WD-css-pseudo-4-20160607/">7 June 2016 Working Draft</a> include: