GREY AND BLACK!
These two colors are always a good combination!, you can wear them in a more relaxing and comfortable way, like this outfit, matching sneakers with a basic t-shirt. But you can wear a more formal t-shirt and match it with a good pair of shoes or boots. The black trousers will do the rest to convert the outfit in a smart one!
I'm wearing TOPMAN for the whole outfit but sneakers from NIKE