Craft\ImagerService::_colorBlend PHP Method

    private function _colorBlend($imagickInstance, $color, $alpha = 1, $composite_flag = \Imagick::COMPOSITE_COLORIZE)
    {
        $draw = new \ImagickDraw();
        $draw->setFillColor($color);
        $width = $imagickInstance->getImageWidth();
        $height = $imagickInstance->getImageHeight();
        $draw->rectangle(0, 0, $width, $height);
        $temporary = new \Imagick();
        $temporary->setBackgroundColor(new \ImagickPixel('transparent'));
        $temporary->newImage($width, $height, new \ImagickPixel('transparent'));
        $temporary->setImageFormat('png32');
        $temporary->drawImage($draw);
        $alphaChannel = clone $imagickInstance;
        $alphaChannel->setImageAlphaChannel(\Imagick::ALPHACHANNEL_EXTRACT);
        $alphaChannel->negateImage(false, \Imagick::CHANNEL_ALL);
        $imagickInstance->setImageClipMask($alphaChannel);
        $clone = clone $imagickInstance;
        $clone->compositeImage($temporary, $composite_flag, 0, 0);
        $clone->setImageOpacity($alpha);
        $imagickInstance->compositeImage($clone, \Imagick::COMPOSITE_DEFAULT, 0, 0);
    }