use Tk;

my $mw = MainWindow->new;
my @colors = qw(red orange yellow green blue purple);

my $listbox = $mw->Listbox(
   -height => 0,
   -foreground => 'white'
)->pack;

foreach my $c (@colors) 
{
   $listbox->insert('end', $c);
   $listbox->itemconfigure('end', -background => $c);
}

MainLoop;