The Luck of the Irish, 1948 in black-and-white or tinted green (Irish sections-garish green, New York black-and-white).

A handsome Tyrone Power plays the perspicacious journalist Steven Fitzgerald, who, unknowingly encounters Horace, a leprechaun while visiting Ireland. Curious about the pookah, he briefly captures him to see his gold, but magnanimously lets him go, which puts the elf, played whimsically by Cecil Kellaway, into his permanent debt. Both he and Nora, the young woman Steve falls in love with in Ireland, end up coming to New York when Steve returns there to take a high-paying sell-out job with Augur (played by Lee J. Cobb), a control-freak newspaper-tycoon running for president, whom Steve disagrees with repeatedly and fundamentally.

Augur’s daughter Francis (played by Jayne Meadows (of The Honeymooners tv series) tries to capture Steve too, but you can guess the predictable outcome, aided by Steve’s new butler, played by Horace. The Irish accents of Horace, Nora, and her father will probably confute and mystify many viewers today. The music cues many of the changing emotional moods throughout the film, including an inappropriate “Greensleeves” (!), but keeps things playfully tuned and moving along.

The wry screenplay by Philip Dunne directed by Henry Koster are top-notch, and both Kellaway and Power are a delightful duo when together in their scenes. There is something special and magical about this oldie which still resonates today for anyone looking for a truly entertaining, delightful piece.

As a postscript, I would mention that Woody Allen obviously borrowed some of the basic conflicts from this classic for his last good movie Midnight in Paris with Hollywood standing in for New York and Paris standing in for Ireland.
Both are amusing, highly-recommended films.