GUI Perl

#!/usr/bin/perl -w
use Tk;
$Tk::strictMotif = 1;
$main = MainWindow->new();
$button1 = $main->Button(-text => "Exit",
                         -command => \&exit_button,
                         -foreground => "orangered" );
$button1->pack();
$button1->configure(-background => "white" );
$button2 = $main->Button(-text => "Choose Color",
                         -command => \&change_color,
                         -foreground => "black", 
                         -background => "steelblue");
$button2->pack();
MainLoop();
sub exit_button {
    print "You pushed the button!\n";
    exit;
}
sub change_color {
    my($color) = $button2->chooseColor(-initialcolor => "maroon" );
    
    if ($color ne "") {
        print "New color is $color\n";
    
        $button2->configure(-background => $color,
                            -foreground => "white",
                            -font => "-*-times-bold-r-normal-20-140-*");
    }
}