There is a darkroom scene in Louis Malle's "Ascenseur pour l'Echafaud" (Elevator to the Scaffold). However, I can't remember if you see the pictures actually being developed and printed under safelight, or if it only shows the characters entering the darkroom after the prints are made and the lights can be turned on. The photos are an important plot element but they're taken as snaps by major characters in the course of events, not by a "photographer" as in someone whose raison d'etre is photography. The movie is black and white so you wouldn't get to see the safelight color.
I'm not too bothered by red safelights in films or showing operations that you would normally do in total darkness. Movies aren't literal depictions, they create an impression to represent events (this underlies Eisenstein's theory of montage, for example). It does bother me more when they make factual howlers that are lazy. For ex, when Wes Anderson mocks up a camera that never existed, it's in service of the Wes Anderson world that isn't quite real, but if you were to see a press photographer with a modern SLR in a 1950s movie, it's just breaking the illusion unintentionally.
P.S. I forgot perhaps the most interesting part of the photo lab in "Ascenseur pour l'Echafaud" - it's at a roadside motel, and this is taken as perfectly normal. Did motels (in France anyway) often have photo labs so that travelers could drop off their snaps for quick turnaround? Who knows?
