Drupal 8: Update allowed values of a select field

MODULENAME.install.php

<?php

/**
 * Update allowed values of background color field.
 */
function MODULENAME_update_8001(&$sandbox) {
  // Load the field.
  $field_config = FieldStorageConfig::loadByName('node', 'field_card_view_background_color');
  // Update the allowed values on it.
  $field_config->setSetting('allowed_values', [
    ['value' => 'teal', 'label' => 'Teal'],
    ['value' => 'orange', 'label' => 'Orange'],
    ['value' => 'blue-light', 'label' => 'Light Blue'],
    ['value' => 'purple', 'label' => 'Purple'],
  ]);
  // Re-save it.
  $field_config->save();
}