Delphi

procedure TMainForm.FormShow(Sender: TObject);
var Owner : HWnd;
begin
Owner:=GetWindow(Handle,GW_OWNER);
ShowWindow(Owner,SW_HIDE);
end;

// Use SW_Show to show back the form

procedure TForm1.FormCreate(Sender:TObject);
begin
Application.HintColor := clAqua; // or another color
Application.HintPause := 250; // 250 mSec before hint is shown
Application.HintHidePause :=3000; // hint disappears after 3 secs
end;