How to add a custom color palette for tableCellProperties ?

Hi, using a hook (in a .module file):

function your_module_ckeditor5_plugin_info_alter(array &$plugin_definitions) {
  if (isset($plugin_definitions['ckeditor5_table'])) {
    $tableDefinition = $plugin_definitions['ckeditor5_table']->toArray();
    $bgColors = [
      '#0a2a3d',
    ];
    $borderColors = ['#eff0f2'];
    $tableDefinition['ckeditor5']['config']['table']['tableProperties'] = [
      'backgroundColors' => $bgColors,
      'borderColors' => $borderColors,
    ];
    $tableDefinition['ckeditor5']['config']['table']['tableCellProperties'] = [
      'backgroundColors' => $bgColors,
      'borderColors' => $borderColors,
    ];

    $plugin_definitions['ckeditor5_table'] = new CKEditor5PluginDefinition($tableDefinition);
  }
}