$width=$xaxiss[0];
$height=$xaxiss[$#xaxiss];
$mygraph->set(
    title       => "$pairs[0]",
    x_label     => "@xaxis",
    X_ORIENT='VERTICAL',
    bar_width        => 18,
    show_values => 1,
    line_width  => 2,
    dclrs       => ['green'] ,
    BACKGROUND='black',
   ) or warn $mygraph->error;

##</code><code>##

---newcode--
$mygraph->set_x_label_font(GD::gdGiantFont);
$mygraph->set_y_label_font(GD::gdGiantFont);