And so the big brown-shoe debate rages on. Speaking at a conference, an unnamed lawyer has told trainees never to wear brown shoes with a blue suit. A study by the government’s Social Mobility Commission in 2016 found that investment banks are less likely to hire men who wear brown shoes to an interview. The former editor of the Daily Mail Paul Dacre hated them (although, to be fair, Dacre hated a lot of things and probably still does). It’s…