Magento PHP script to delete all values of an attribute

magento-delete-attribute-options.php

<?php
$attribute_code = 'fashion_colour';
$attribute = Mage::getModel('eav/config')->getAttribute('catalog_product', $attribute_code);
$options = $attribute->getSource()->getAllOptions();
$optionsDelete = array();
$optionsValue = array();
foreach($options as $option) {
    if (in_array($option['label'], $optionsValue)) {
        $optionsDelete['delete'][$option['value']] = true;
        $optionsDelete['value'][$option['value']] = true;
    } else {
        $optionsValue[] = $option['label'];
    }
}
var_dump($optionsDelete);
$installer = new Mage_Eav_Model_Entity_Setup('core_setup');
$installer->addAttributeOption($optionsDelete);
?>