String

<v-data-table
     :headers="headers"
     :items="lines"
      item-class="color"
      ...
</v-data-table>

data: () => ({
     lineas: [
       {text: 'Uai', color: 'red-line'},
       {text: 'HH', color: 'red-line'},
       {text: 'Liujiaji', color: 'blue-line'},
      ],
})

<style>
    .blue-line td {
        color: green;
    }
    .red-line td{
        color: red;
    }
</style>

Function

<v-data-table
    :headers="headers"
    :items="items"
    :item-class="rowClass"
></v-data-table>

rowClass(item) {
        console.log(item)
        const rowClass = 'liujiaji-tr-class'
        return rowClass;
    }

<style lang="css">
.liujiaji-tr-class {
  background-color: green;
}
</style>

hover颜色

.liujiaji-tr-class:hover {
  background-color: green !important;
}

以上酌情加 ::v-deep