Multiple background colors?

codepen: http://codepen.io/Mooshy6665f/pen/apxOJX

I am working on the portfolio project. I would like to separate different sections using different background colors. The posted codepen is a quick markup of what I am trying to do. Is there a way to accomplish this without the white spaces in between the divs?

p {
  margin: 0;
}

p elements have a default margin.

is this what you looking for?

As h4m3d said, a lot of the elements have its default margin. Disable those if you want.