ImageMagick pixel color extraction from CMYK image

output.txt

##
## Ubuntu Bionic with PHP 7.2.7 and ImageMagick 6.9.7
##

>>> $resource = new Imagick("tests/images/bookcover.jpg")
=> Imagick {#2286}
>>> $resource->getImagePixelColor(20, 20)->getColor(true)
=> [
     "r" => 0.0,
     "g" => 0.10196078431373,
     "b" => 0.82745098039216,
     "a" => 1.0,
   ]
>>> $resource->transformImageColorspace(Imagick::COLORSPACE_RGB)
=> true
>>> $resource->getImagePixelColor(20, 20)->getColor(true)
=> [
     "r" => 1.0,
     "g" => 0.78353551537346,
     "b" => 0.025192645151446,
     "a" => 1.0,
   ]
>>> $resource->transformImageColorspace(Imagick::COLORSPACE_SRGB)
=> true
>>> $resource->getImagePixelColor(20, 20)->getColor(true)
=> [
     "r" => 1.0,
     "g" => 0.89803921568627,
     "b" => 0.17256427862974,
     "a" => 1.0,
   ]