How to change the color of Draw("colz")

I have an object : TH2F *f, how to change the color when draw it with the option “colz”?

{
   TF2 *f2 = new TF2("f2","0.1+1000*((1-(x-2)*(x-2))*(1-(y-2)*(y-2)))",1,3,1,3);
   Int_t ncol = 100;
   Int_t colors[ncol];
   TColor *col;
   Double_t dg=1/(Double_t)ncol;
   Double_t grey=0;
   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;
   }
   f2->SetContour(ncol);
   gStyle->SetPalette(100,colors);
   f2->Draw("colz");
}

Thanks! :smiley: