I’ve talked about researching and making sure the photograph you have can be sold once you colorize it. For instance; you find a rare photograph of Clark Gable in the military and want to sell prints. The story of the famous Hollywood star in the military is one that will pull in customers (Hitler told his soldiers to hunt down Clark Gable, he wanted the actor and our soldiers took him into hiding), but is Clark one that will get you in trouble?
For example, this photograph. Where do you go to find out Clark Gable is a name that won’t get you in trouble? It’s easy enough actually; contact Hollywood historic societies and find out what you can. If there’s no trouble there, don’t forget to search WWII historic societies because a lot of times they are VERY strict about the actors who served in the war (John Wayne can’t be sold because of his WWII films, and other reason).
What about someone who wasn’t connected to the military? Maybe someone like Bing Crosby
Bing was a successful singer (known also as the Crooner), who had a wonderful friendship with Bob Hope (they did several films known as “The Road to…”, I recommend them if you’re into silly slapstick comedy). He’s best known now for his role in White Christmas and Christmas albums….so would one just go to Hollywood historical societies to research photographs of him? Not quite. His years in music will mean you need to check whatever music historical societies, and he did have a career in vaudeville if I remember so you may have to look there too. There’s still a large fanbase for him, so it’s kind of tricky if Bing is off limits or not; it could depend on what photograph you use.
Historic societies have all the information you need and people are always willing to work with you. They are fully aware that there’s a popularity for colorizing vintage photographs and want to help make it easy on you. Hope this helps!