[css-color-adjust-4] Add note that light doesn't mean black-on-white. #3983

Author: fantasai

css-color-adjust-1/Overview.bs

@@ -160,6 +160,13 @@ Opting Into a Preferred Color Scheme: the 'color-scheme' property {#color-scheme
 			is still not guaranteed to have any effect on the rendering of the element.
 	</dl>
 
+	Note: “Light” and “Dark” modes are not specific color palettes.
+	For example,
+	both a stark black-on-white scheme and a sepia dark-on-tan scheme
+	would be considered “Light” color schemes.
+	To ensure particular foreground or background colors,
+	they need to be specified explicitly.
+
 Finding the Used Color Scheme {#color-scheme-processing}
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