div {
  width:250px;
  height:100px;
  border:5px solid #000000;
  color:black;font-weight:bold;
  text-align:center;
}
div#d1{
  background-color:red;
  margin:15px;
}
div#d2{
  background-color:green;
  margin:15px;
}
div#d3{
    background-color:blue;
    margin:15px;
}
div#d4{
  background-color:yellow;
  margin:15px;
}