.maastricht{
    width: 20px;
    height: 20px;
    float: left;
}

.rij{
    clear: both;
}

.maastricht.white{
    border: 1px solid black;
    background-color: white;
}

.maastricht.black{
    border: 1px solid black;
    background-color: black;
}
.maastricht.red{
    border: 1px solid black;
    background-color: red;
}
.maastricht.green{
    border: 1px solid black;
    background-color: green;
}
.maastricht.dgreen{
    border: 1px solid black;
    background-color: darkgreen;
}