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;
}