Rolinda Sharples’s 1817 painting of the Cloak-Room, Clifton Assembly Rooms is a familiar one to most Jane Austen fans. This image graces many book covers and has been used for depicting life in the Regency era. Looking closely, one sees that the assembled party seem to be enjoying the occasion as they wait and chat. A lady’s maid is helping a woman exchange her shoes, a man holds a lady’s fan, and the ladies are wearing an assortment of pale dresses, and colorful headwear and shawls. John Harvey, author of Men in Black, 1996, a book about the predeliction men have had over the centuries for wearing black, noted on p. 37 that Rolinda’s painting illustrates the direction that fashion was taking in the 19th century:
The white-haired man to the left is dressed in the older style, with light-coloured knee-breeches and lighter stockings. The stooping man to the right is a transitional type, wearing black knee-breeches, black stockings.
Cloak Room, Clifton Assembly Room, 1817, Rolinda Sharples
The man to centre-left is dressed as Brummel dressed, in skin-tight black trousers.
The above style and the two previous styles would have been familiar to Jane Austen, for she died the same year that this painting was made.
It is the man to the right of him, in looser black trousers, who is dresed as the century was in future to dress. The men at Mr. Rochester’s party [in Jane Eyre] would all be in his style.
These links do not describe formal menswear, per se, but the are descriptive of men’s clothes of the era:
Jane Austen's World 