[css-pseudo-4] Clarify that base element text decorations lose their colors to pseudo-element's 'color' when it is specified. w3c#2850

Author: fantasai

css-pseudo-4/Overview.bs

@@ -637,6 +637,13 @@ Painting the Highlight</h3>
   over the text’s original decorations
   and are all drawn, in their own colors.
 
+  Note: The element’s own text decorations
+  (both <a href="https://www.w3.org/TR/css-text-decor/#line-decoration">line decorations</a>
+  and <a href="https://www.w3.org/TR/css-text-decor/#emphasis-marks">emphasis marks</a>)
+  are thus drawn in the pseudo-element’s own 'color'
+  when that is not ''currentColor'',
+  regardless of their original color or fill specifications.
+
   Issue: What should happen with text shadows?
   Drawing them in their original color is disconcerting if that color is not a shade of gray.
   Maybe if the overlay has a background, suppress any text shadows below it?