sub threadFunktion{
  my $s_red=0;
  my $s_green=0;
  my $s_blue=0;

  while(1){
    $s_blue=$s_blue+10;
    $farbe = sprintf("#%02x%02x%02x",$s_red,$s_green,$s_blue);
    $c->itemconfigure('tags',-fill =>$farbe);
    sleep(1);
  }
}