Do switches and sockets have to match?

The simple answer is no, sockets and switches do not have to match. In fact there are many occasions when we would suggest choosing a different finish for the sockets and switches in the same room. While for some room, like living rooms and dining rooms, it is still normal to use the same colour switches and sockets, there are some room, like the kitchen, where taking a mix-and match approach can really work. 

Especially where you are fixing the switches and sockets to different surfaces, for instance if you are putting the sockets on a tiled wall, and the switches on a plastered wall, it can work really well to switch it up. 

There are also times when you want to make it easy to spot the light switch, but want the sockets to blend in with the background. That could mean putting a white socket on a white wall, but then putting a more stand-out colour, like copper switches, on the wall.