When a scene in a movie or tv show is set at a very sad, depressing, gloomy place there is often a blue-ish og red-ish glow to everything. This gives a pretty dark feeling and underlines the sad/scary suspense.
The name comes from the episodes The O.C. When the setting is chino, wether the characters have travelled there or not, there is always a gloomy blue-ish glow to everything.