Highlight escaped characters in default Light+ (Fix #48638) (#48746)

* highlight escaped characters in default Light+(Fix #48638)

* fix constant.character.escape

* fix constant.character.escape again

extensions/theme-defaults/themes/light_plus.json

@@ -156,7 +156,7 @@
 		{
 			"scope": "constant.character.escape",
 			"settings": {
-				"foreground": "#a31515"
+				"foreground": "#ff0000"
 			}
 		}