Magento: Get all attribute values (colors, sizes, etc..)

require_once('app/Mage.php');
umask(0);
Mage::app('admin');
//set_time_limit(0);
$attribute = Mage::getModel('eav/config')->getAttribute('catalog_product', 'color');
$colors = array();
foreach ($attribute->getSource()->getAllOptions(true) as $option) {
        $colors[] = $option['label'];
}
sort($colors);
foreach($colors as $lbl) {
    echo "<span style='background-color:lightgrey'>".$lbl . "</span>";
        echo "<br>";
}