$//$ route handlers below are listed in order$//1$:app.put$(\text{'}/$:green', $($req$,$ res$)=>\{...\})$;$//2$:app.put$(\text{'}/$color$\text{'},($req$,$ res$)=>\{...\})$;$//3$:app.put$(\text{'}/$color$/$:green', $($req$,$ res$)=>\{...\})$;$//4$:app.put$(\text{'}/$:color', $($req$,$ res$)=>\{...\})$;