According to the Duke of Windsor, his Victorian father favored dark brown suits. This could be puzzling, because we have heard so much about proper city dress being navy blue or grey. But in the 1800th Century, when business men wore frock coats and cutaways, warmer colours in dark shades were common for business wear. Indeed, the black frock coat is a symbol of Victorian times, but in reality more colours were in use in the city. That we know from paintings, descriptions and fashion plates in journals like the Minister’s Gazette of Fashion.
In other words, it doesn’t have to be wrong to wear a brown suit in the city, if we look at it from historical point of view. However, since so few do it, and since blue and grey have been established as the only acceptable business colours today, a brown suit will stand out, which, of course, shouldn’t stop us from wearing it. Brown works well with most complexions and hair colours.
Source: The Journal of Style in Italy
I have rather limited knowledge of what other colours to combine brown with.
Besides blue, I think green, yellow and red all can complement brown.
Thank you.