A tuxedo (American English, also colloquially known as “tux”) or dinner suit or dinner jacket (British English – “dinner jacket” – describing both jacket and trousers is held to be more “correct” – “dinner suit” is regarded as a solecism) is a formal evening suit distinguished primarily by satin or grosgrain facings on the jacket’s lapels and buttons and a similar stripe along the outseam of the trousers. The suit is typically black or midnight blue depending on choice of wear and commonly worn with a formal shirt, shoes and other accessories, most traditionally in the form prescribed by the black tie dress code.
The earliest tuxedo jackets were of the same black material as the dress coat with one, two or no buttons and a shawl collar faced in satin or ribbed silk. By the turn of the twentieth century the peaked lapel was equally popular and the one-button model had become standard. When trousers were sold with the jacket they were of the same material. Edwardian dandies often opted for Oxford grey or a very dark blue for their evening wear.
Mens Tuxedo Fashion