Having a black shirt and pants, in addition to those same gray clothes, is usually common. So the combination formed by a black piece and another in a shade of gray will be a basic, understated and understated composition. But it will not favor abusing it.
Gray is more colorful with other colors like black, blue or brown, and of course even more with the rest. Black is what it is.
When the pants are black the shoe can not be another, but if it turns gray, we can venture with the browns for the shoes. Darker always the tone of the shoe than that of the pants. The only thing that can give life to this outfit are the complements, although many are the ones that we prefer will not strive in it. This outfit is fine as it is.
With this set in gray and black we present an image as relaxed and elegant as taciturn, so it is not appropriate to abuse its continuity. We do not have to start with big combinations to get it right, but to get it right we have to start combining ... even if it's not with great results.