Print striped table

HTML

<script src="http://netdna.bootstrapcdn.com/bootstrap/3.2.0/js/bootstrap.min.js"></script>
<link rel="stylesheet" href="http://netdna.bootstrapcdn.com/bootstrap/3.2.0/css/bootstrap.min.css">
<table class="table table-condensed table-striped">
                                <thead>
                                    <tr>
                                        <td><strong>Código</strong></td>
                                        <td class="text-left"><strong>Produto</strong></td>
                                        <td class="text-left"><strong>Observação</strong></td>
                                        <td class="text-right"><strong>Qtd.</strong></td>
                                        <td class="text-right"><strong>Valor Un.</strong></td>
                                        <td class="text-right"><strong>Valor Total</strong></td>
                                    </tr>
                                </thead>
                                <tbody>
                                    
                                    
                                        <tr>
                                            <td>66</td>
                                            <td class="text-left">ANTIGRIPAL LIMAO</td>
                                            <td class="text-left"></td>
                                            <td class="text-right">2</td>
                                            <td class="text-right">R$24,00</td>
                                            <td class="text-right">R$48,00</td>
                                        </tr>

                                    
                                        <tr>
                                            <td>117</td>
                                            <td class="text-left">ANTIGRIPAL FARMEL</td>
                                            <td class="text-left"></td>
                                            <td class="text-right">4</td>
                  ...

CSS

tr:nth-child(even) {
  background-color: red;
}


tr:nth-child(odd) {
  background-color: white;
}

@media print {    
  tr:nth-child(even) {
    background-color: red !important;
    -webkit-print-color-adjust: exact; 
  }
}

JavaScript

window.print();