Alternatively, the user might be using "blue film" as a metaphor for something else, or as a term from a specific niche. But without more context, it's hard to say.
Alternatively, silent films often have a blue tint due to early film stock technology. Or films that use blue lighting for mood, like in film noir. indian blue film video
Given all this, I think the safest route is to address the possible interpretations, clarify the term, and then provide classic and vintage movie recommendations, perhaps highlighting those with notable color palettes or specific themes related to blue, while avoiding any explicit content. Alternatively, the user might be using "blue film"
Alternatively, maybe the user is thinking of "blue" as in the term "the blues," like emotional tones, and wants classic movies with melancholic themes. But that's speculative. Or films that use blue lighting for mood, like in film noir