Example

$imagick = new \Imagick();
$imagick->newPseudoImage(640, 480, "magick:logo");
$histogramElements = $imagick->getImageHistogram();
$lastColor = array_pop($histogramElements);
$color = $lastColor->getColor();
$output = sprintf(
    "ColorCount last pixel = %d\nColor is R %d G %d B %d",
    $lastColor->getColorCount(),
    $color['r'],
    $color['g'],
    $color['b']
);

return nl2br($output);