.custom-checkbox {
    background-color: #f5f5f5; /* 设置背景色为浅灰色 */
}

<?php
    $this->registerCssFile('@web/css/custom.css');
?>

<?= GridView::widget([
    'dataProvider' => $dataProvider,
    'columns' => [
        ['class' => 'yii\grid\SerialColumn'],
        [
            'class' => 'yii\grid\CheckboxColumn',
            'checkboxOptions' => function ($model, $key, $index, $column) {
                return ['class' => 'custom-checkbox'];
            }
        ],
        // 其他列配置
    ],
]); ?>