table,td{
    border: 1px solid #000;
    border-collapse: collapse;
    width: 500px; /*solo a los objetivos tipos <table>*/
    height: 50px; /*solo a los objetos <td onclick="mostrarReina(this);"></td>*/
}
tr:nth-child(even)
td:nth-child(even),
tr:nth-child(odd)
td:nth-child(odd){
    background-color: #B58863;
}
tr:nth-child(odd)
td:nth-child(even),
tr:nth-child(even)
td:nth-child(odd){
    background-color: #F0D9B5;
}