.R1,.R2,.R3,.R4,.R5,.R6 {
    width: 35px;
    display: inline-block;
    padding: 2px;
    border-radius: 3px;
    text-align: center;
    line-height: 2;
}
.R1 {
  background-color: #666;
}
.R2 {
        background-color: #3ca381;
}
.R3 {
        background-color: #0c87f1;
}
.R4 {
        background-color: #821ce2;
}
.R5 {
        background-color: #e6a22eb3;
}
.R6 {
        background-color: #ff4500;
}