Who played Colonel Pickering in the 1964 film 'My Fair Lady'?

'My Fair Lady' is a 1964 American musical film adapted from the Lerner and Loewe eponymous stage musical based on the 1913 stage play 'Pygmalion' by George Bernard Shaw. With a screenplay by Alan Jay Lerner and directed by George Cukor, the film depicts a poor Cockney flower seller named Eliza Doolittle who overhears an arrogant phonetics professor, Henry Higgins, as he casually wagers that he could teach her to speak "proper" English, thereby making her presentable in the high society of Edwardian London.

In Edwardian London, Professor Henry Higgins (Rex Harrison), a scholar of phonetics, believes that the accent and tone of one's voice determines a person's prospects in society. In Covent Garden one evening, he boasts to a new acquaintance, Colonel Hugh Pickering (Wilfrid Hyde-White), himself an expert in phonetics, that he could teach any person to speak in a way that he could pass them off as a duke or duchess at an embassy ball. Higgins selects as an example a young flower seller, Eliza Doolittle (Audrey Hepburn), who has a strong Cockney accent. Eliza's ambition is to work in a flower shop, but her thick accent makes her unsuitable. Having come from India to meet Higgins, Pickering is invited to stay with the professor. The following morning, Eliza shows up at Higgins' home, seeking lessons.