<?php
$options = array
(
    'hostname' => SOLR_SERVER_HOSTNAME,
    'login'    => SOLR_SERVER_USERNAME,
    'password' => SOLR_SERVER_PASSWORD,
    'port'     => SOLR_SERVER_PORT,
);
$client = new SolrClient($options);
$query = new SolrQuery();
$query->setQuery($query);
$query->addField('price')->addField('color');
$query->setFacet(true);
$query->addFacetField('price')->addFacetField('color');
$query_response = $client->query($query);
$response = $query_response->getResponse();
print_r($response['facet_counts']['facet_fields']);
?>
     
    The above example will output
something similar to:
SolrObject Object
(
    [color] => SolrObject Object
        (
            [blue] => 20
            [green] => 100
        )
)