Director Martin Scorsese designed each year in this movie to look just the way a color movie from that time period would look. Achieved mainly through digitally enhanced post-production, Scorsese re-created the look of Cinecolor and two-strip Technicolor. Watch in particular for the scene where Howard Hughes (Leonardo DiCaprio) meets Errol Flynn (Jude Law) in the club. Hughes is served precisely placed peas on a plate, and they appear blue or turquoise, just as they'd have looked in the two-strip Technicolor process. As Hughes ages throughout the movie, the color gets more sophisticated and full-bodied.
Leonardo DiCaprio spent a day with Jane Russell to hear her memories and impressions of Howard Hughes. She was impressed with DiCaprio's visit and told him that Hughes was a quiet yet extremely stubborn man who always got his way in the end.
In preparation for her role as Katharine Hepburn, Cate Blanchett learned to play tennis and golf, and took cold showers, for which Hepburn was known.
Director Martin Scorsese requested that Cate Blanchett watch the first fifteen movies of Katharine Hepburn, to learn her mannerism and her poise.
Also in preparation for his role as Howard Hughes, Leonardo DiCaprio spent some time with an O.C.D. patient named Edward. He advised him on several different aspects of the condition, in particular, the tendency to repeat sentences over and over, as in the scene where Hughes repeatedly asks to see the blueprints for the Hercules.
Loudon Wainwright III, Rufus Wainwright, Martha Wainwright: Each appear as vocalists at the Coconut Grove nightclub during different eras. Loudon Wainwright guest starred in M*A*S*H (1972), which starred Alan Alda.
Anne V. Coates: The editor of Lawrence of Arabia (1962) and The Elephant Man (1980) appears as one of Howard Hughes' editors, putting together the initial cut of Hell's Angels (1930).
Martin Scorsese: In a tuxedo and slicked hair, pulling a woman from behind Hughes as he walks the red carpet with Hepburn. Scorsese also provided the voice of the projectionist, to whom Hughes talks, in the screening room.