use Imager;

$img = Imager->new(xsize=>700, ysize => 500, channels => 4);

# setting Imager::Color->new($red, $green, $blue, $alpha);
$blue = Imager::Color->new( 0, 0, 255, 255);
$red = Imager::Color->new( 255, 0, 0, 63);

$img->box(color => $blue, xmin=>10, ymin=>30, xmax=>200, ymax=>300, filled=> 1);
$img->box(color => $red, xmin=>50, ymin=>80, xmax=>250, ymax=>350, filled=> 1);

my $outfile = "foo.png";

$img->write(file=>$outfile) or die $img->errstr;