When Orson Hodge (Kyle MacLachlan) is on the phone with the manager at Bree Hodge's bank, Orson tells the manager that he doesn't know Bree's true hair color (alluding that Bree's natural hair color is not red). Ironically, Marcia Cross' (Bree's) true hair color IS red.
The title is a line from the song "Liaisons", from Stephen Sondheim's musical "A Little Night Music." (1973)