from Cinegraphic.net:

How to Tint and Tone B&W Film

story © internetted, September 25, 2011 all rights reserved.

URL: https://www.cinegraphic.net/article.php?story=20110925071921172

This is a historical how-to:

I recently acquired a copy of the rare Tinting and Toning of Eastman Positive Motion Picture Film, second edition from 1918. I have made a .pdf of the text and it's posted (3.4 Mb download) as a service for anyone interested in the details of how these colorizing processes worked. It contains the instructions and formulae for creating the hues used in the early decades of film production.

One of the things that I happen to believe is crucial, even essential, is the accessibility of this type of primary source material for people doing research. Also take a look at this very interesting article by Paolo Cherchi Usai: "The Color of Nitrate: Some Factual Observations on Tinting and Toning Manuals for Silent Films." from Image magazine.

Posting this kind of material, making it available, is what makes the internet useful as a research tool. It's what every archive should be doing, and is the reason the Library of Congress is so interesting to look at online.