Often in movies, they use a brownish looking tone to make movies seem “older” to fit with the period the story is set in. This brown color toning is called “sepia.” One example is “The Quick and the Dead”
What is the name of the color tone for the bluish tone used in films like “Hart’s War?”
Preussian Blue.
Cite?
I exclude a digital toning process.
Blue toning of traditional silverhalide based films is possible with 3 well known processes:
Blue toning with goldchloride (AuCl2). This gives deep blue tones, almost black. It is, due to it’s ingredients however, extremely expensive. I don’t think this is the process used.
Using an additive called “benzotriazole” during the development process. This yields in very blue black tones, but not very blue.
Iron Blue toning.
The active ingredients of a blue toner are potassium ferricyanide, a bleaching agent that oxidises silver to silver ferrocyanide, and a ferric iron salt (any of several, depending on the type of formula) which reacts with the bleached silver to form a precipitate of ferric ferrocyanide (this is the blue dye= Preussian Blue). In a direct toner, bleaching and toning take place at the same time, adding ferric ferrocyanide to the silver image while its conversion to silver ferrocyanide is taking place.
hope this helps, Z