{
   Int_t ncol = 50;
   Int_t colors[ncol];
   TColor *col;
   Double_t dg=1/(Double_t)ncol;
   Double_t grey=100;
   for (Int_t i=0; i<ncol; i++) {
      colors[i]= i+100;
      col = gROOT->GetColor(colors[i]);
      col->SetRGB(grey, grey, grey);
      grey = grey-dg;
   }
   gStyle->SetPalette(ncol,colors);

   TF2 *f2 = new TF2("f2","0.1+1000*((1-(x-2)*(x-2))*(1-(y-2)*(y-2)))",1,3,1,3);  
   f2->SetContour(ncol);
// gStyle->SetPalette(1);
// f2->Draw("colz");
   f2->Draw("cont4 z");
}