Fix #62446, increase opacity of selection highlight bg

extensions/theme-defaults/themes/light_defaults.json

@@ -7,7 +7,7 @@
 		"editor.inactiveSelectionBackground": "#E5EBF1",
 		"editorIndentGuide.background": "#D3D3D3",
 		"editorIndentGuide.activeBackground": "#939393",
-		"editor.selectionHighlightBackground": "#ADD6FF4D",
+		"editor.selectionHighlightBackground": "#ADD6FF80",
 		"editorSuggestWidget.background": "#F3F3F3",
 		"activityBarBadge.background": "#007ACC",
 		"sideBarTitle.foreground": "#6F6F6F",