Colorize, updated 22.06.2019
Colorizing old black and white pictures became a bit of a relaxing hobby in recent times. Here are some results. I use an ipad Pro with Affinity Photo and the Apple pencil to do the task.
Junghans Terrassenbau Taschenuhrmontage, 1920er
Picture courtesey of Junghans Uhrenfabrik Junghans GmbH & Co.KG
Junghans Grossuhrmontage, 1920er
Picture courtesey of Junghans Uhrenfabrik Junghans GmbH & Co.KG
Walter Mittelholzer mit Flugpassagieren vor einer Junkers F 13 der Ad Astra Aero AG in Dübendorf
V.l.n.r.: unbekannt, Rudolf Streuli, W. K. Mocesson?, R. Maurer, W. K. Streuli und Walter Mittelholzer
Ken Wallis testing a version of his WA.116 gyroplane during the early 1960s for the British military.
Pitcairn PA-18 Autogiro, Jean Harlow & Tito Falconi, Southern California, 1933. Photo by Wayne "Dick" Whittington.

An acrobat (possibly Marilyn Rich) dangles from a hovering Bell 47B helicopter (r/n NC102B) during a demonstration at the the National Air Races, Cleveland, Ohio.
Junkers Flugzeugwerke AG, ca. 1919, Folks standing on a F13 wing.
Original picture from the ETH-Bibliothek Zürich, Bildarchiv / Fotograf: Unbekannt