td{

    height: 50px;
    width: 50px;
}

tr:nth-child(odd) td:nth-child(odd){

    background-color: orangered;
}

tr:nth-child(odd) td:nth-child(even){

    background-color:bisque;

}
tr:nth-child(even) td:nth-child(even){

    background-color:orangered;

}
tr:nth-child(even) td:nth-child(odd){

    background-color:bisque

}
td{

    font-size: 30px;
    text-align: center;
}