Example

$color = new \ImagickPixel('brown');
$color->setColorValue(\Imagick::COLOR_ALPHA, 0.25);
$output .= "<h4>Standard values</h4>";
foreach ($color->getColor() as $key => $value) {
    $output .= "$key : $value <br/>";
}
$output .= "<br/>";
$output .= "<h4>Normalized values</h4>";
foreach ($color->getColor(true) as $key => $value) {
    $output .= "$key : $value <br/>";
}