.grey {
height: 10em;
width: 10em;
background-color: grey;
border: 1px solid black;
}
.red {
height: 10em;
width: 10em;
background-color: red;
border:1px solid black;
}
.green {
height: 10em;
width: 10em;
background-color: green;
border:1px solid black;
}