Specifies the color of a background rectangle to place under text annotations.
Background color
 
Stroke color
 
Fill color
 
Text under color
 
Specifies the color of a background rectangle to place under text annotations.
Parameters
under_colorImagickPixelthe under color
function setTextUnderColor($strokeColor, $fillColor, $backgroundColor, $textUnderColor)
{
    $draw = new \ImagickDraw();

    $draw->setStrokeColor($strokeColor);
    $draw->setFillColor($fillColor);
    $draw->setStrokeWidth(2);
    $draw->setFontSize(72);
    $draw->annotation(50, 75, "Lorem Ipsum!");
    $draw->setTextUnderColor($textUnderColor);
    $draw->annotation(50, 175, "Lorem Ipsum!");

    $imagick = new \Imagick();
    $imagick->newImage(500, 500, $backgroundColor);
    $imagick->setImageFormat("png");

    $imagick->drawImage($draw);

    header("Content-Type: image/png");
    echo $imagick->getImageBlob();
}