JSFiddle - React, Tailwind, and code Playground

HTML

<table>
    <tr>
        <td> a </td><td> b </td>
    </tr>
    <tr>
        <td> a </td><td> b </td>
    </tr>
    <tr>
        <td> a </td><td> b </td>
    </tr>
    <tr>
        <td> a </td><td> b </td>
    </tr>
    <tr>
        <td> a </td><td> b </td>
    </tr>
    <tr>
        <td> a </td><td> b </td>
    </tr>
</table>

CSS

table {
    background:#fff;
    width:100%;
}
tr:nth-child(2n+2) {
    background:#ccc;
}