In which film is there a color sequence, the only color footage of Jean Harlow's career?

'Hell's Angels' is a 1930 Pre-Code independently made American epic aviation war film, directed and produced by Howard Hughes, that stars Ben Lyon, James Hall, and Jean Harlow. The film, which was written by Harry Behn and Howard Estabrook, was released by United Artists. Originally shot as a silent film, Hughes retooled Hell's Angels over a lengthy gestation period. Most of the film is in black-and-white, but there is one color sequence, the only color footage of Harlow's career.

Controversy during the 'Hell's Angels' production contributed to the film's notoriety, including the accidental deaths of several pilots, an inflated budget, a lawsuit against a competitor (The Dawn Patrol), and repeated postponements of the release date. 'Hell's Angels' was one of the highest-grossing films of the early sound era, but despite this it still failed to recover its exorbitant production costs. It is now hailed as one of the screen's first sound action films.