how do i remove white background in node inside virtual TVirtualStringTree?

[Zacherl]

What exactly are you trying to do?

You can set a custom color for each row like this:

Delphi-Quellcode:

procedure TfrmMain.EditorTreeBeforeItemErase(Sender: TBaseVirtualTree; TargetCanvas: TCanvas;
  Node: PVirtualNode; ItemRect: TRect; var ItemColor: TColor; var EraseAction: TItemEraseAction);
begin
  EraseAction := eaColor;
  ItemColor := clBlue;
end;

If you like to use colored rows while using a background image, try this:
http://stackoverflow.com/a/10537589