Colour and its complements have always fascinated me. I think it began in art class. The idea of complementary colours (or contrasting ones, as the same pairs are also described – which has interesting ramifications in itself) I found wondrous. Why should these particular pigments sit in such a cosy circle and produce such varying secondary colours when they are mixed?

Wonder was only enhanced by the rules of physics, learnt a few years later. The primary colours are different with light? But they mix to produce the same things? That makes no sense, no matter how many wave diagrams you show me.

Today, the fascination with colour is expressed in shirt/tie and sock/shoe combinations. Sad really.

With black shoes, there broadly two colour options. Either stay with the dark, rich tone of the leather and try to add a little body to it – deep greens and purples probably – or say ‘to hell with it’ and go for the highest contrast – bright yellow or, more profitably, red.

We’ll deal with brights and black another day. For the moment let’s focus on purple. A rich colour, a royal colour, a religious colour: purple is unusual but could never be accused of frippery. Placed between navy pinstripes and black oxfords, for example, it is serious enough for the dignity of business. But how much more excitement and pleasure for the eye does it give than trouser-matching navy?

Some confess to feeling rather restricted by black shoes. One or two friends in the law have complained that they just don’t have any options, so conservative are the tastes of their employers. Well, first there are some damned exciting black shoes out there. But second, see if your employer can find any grounds for objecting to purple. It’s my favourite and it could soon be yours, too.