SetFrameFillColor by kWhite

Hi,
I try to use can->SetFrameFillColor() to set frame fill color in kWhite or 0, but it seems not working only kWhite or 0.

test_can_color() {
  TCanvas * can = new TCanvas("can", "can", 800, 600);
  TH1F * h = new TH1F("h", "h", 100, -3, 3);
  h->FillRandom("gaus", 5000);
  h->Draw();
  can->SetFrameFillColor(kRed); //it doesn't work for kWhite or 0!
}

Cheers,
Zhiyi.
Ubuntu: 8.04 ROOT: 5.20

Just for your reference, If I set it as 10 instead of 0 or kWhite, then works as a white color.

Zhiyi.