In London Holiday, Darcy spends some time *gasp* in disguise as a footman. While the circumstance is terribly uncomfortable for him, it does afford him some freedoms he would not have had otherwise. However, life as a Regency era footman was no cake walk. If your name did not happen to be Fitzwilliam Darcy, and if you did not get to replace your livery with a custom-tailored set of clothing the next day, what would your life have been like?
First of all, footmen were typically fit, young, handsome, and tall. Darcy would have looked rather fetching in livery, and it is not so surprising that there might have been a set somewhere that would fit him. The footman was almost a functional piece of furniture in a wealthy household, for his appearance was one of the first considerations upon hiring him. His job, as Elizabeth says in the book, is to be handsome, and a well-turned calf which showed well in silk stockings was considered a job qualification.