Another angle: maybe the user is referring to films from the "blue period" in art history, but that's a Spanish artist's period (Pablo Picasso). Not sure how that connects to movies.
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.
Therefore, perhaps the best approach is to politely ask for clarification, but since the user wants a complete post, maybe I can proceed assuming the non-explicit meaning and focus on vintage films with blue color themes or related to the term "blue" in other contexts.