protected function colorArgs($args)
{
if ($args[0] != 'list' || count($args[2]) < 2) {
return array(array('color', 0, 0, 0), 0);
}
list($color, $delta) = $args[2];
$color = $this->assertColor($color);
$delta = floatval($delta[1]);
return array($color, $delta);
}