Subtle or intentional color cast across the entire frame — cool tones for dread, warm for intimacy. Analog: chemical bath; digital: grading in post.
You know this from editing: The colorist applies a global tint to the entire frame – not to correct errors, but to make an emotional statement. That's virage. A continuous color cast that permeates the mood of an entire sequence or film. Cold – blue tint for grief, abandonment, night. Warm – amber, orange for nostalgia, warmth, danger. Basically, one of the oldest techniques in cinema, only the tools have changed.
Historically, virage was a chemical matter: black and white films were bathed in dye solutions to give them a sepia, red, or blue tint. Nosferatu, Metropolis – these classics worked with it. The tint was directly in the emulsion, inseparable from the material. Today, you do this digitally: in DaVinci, in Final Cut, wherever your color correction is running. A lift in the shadows, a gamma shift in the midtones, and the atmosphere is complete.
You rarely notice virage directly on set – unless you're shooting in extreme lighting situations (sunrise, artificial light). The colorist works on it later. But: As a DoP, you need a feel for what the film can bear. An extreme blue virage needs contrast, otherwise everything looks flat. Warm virages are less forgiving of exposure errors – overexposed looks washed out. So you always set your lighting with the later color processing in mind.
Important: Virage is not an error to be concealed – it is a conscious design decision. Stalker by Tarkovsky, Moonlight by Jenkins – both use virage as a structural stylistic device. Warm scenes get a different tint than cold ones to separate spaces and times. This works hand in hand with lighting and motif selection. In editing, we also speak of color grading when the virage is part of a complex color strategy. Difference: Virage is the overall tone, grading is the differentiated control of all color areas.
For practice: Discuss virage plans early with the director and editor. A film that is completely warm viraged requires different lighting values than a cold one. This determines your aperture, your use of filters, your choice of position. And remember – extreme virages age quickly. Fashion becomes kitsch. The most subtle virage often lasts the longest.