As for my previous reported patch on TeeTree panel, there is another issue for drawing the text of TTreeNodeshape. The system color values (like clWindowText) are not mapped into rgb values, and as these system values are negative, they are drawn as transparent values, thus become invisible.

Here's the fix I come up with:

Procedure TTreeNodeShape.SetCanvasFont(const ACanvas:TCanvas3D);
begin
  if not Assigned(Tree) then
     ACanvas.AssignFont(InternalFont)
  else

  with Tree do
  if Self.FSelected and
     (Selected.TextColor<>clNone) and
     (not Designing) then
  begin
    ACanvas.AssignFont(InternalFont);
    ACanvas.Font.Color:=Selected.TextColor;
  end
  else
  begin
    // HotTrack ...
    if IMouseInside and (not Designing) and
       HotTrack.Active then
    begin
      if HotTrack.UseFont then
         ACanvas.AssignFont(HotTrack.Font)
      else
      if HotTrack.HotLink then
      begin
        ACanvas.AssignFont(InternalFont);
        with ACanvas.Font do Style:=Style+[{$IFDEF FMX}TFontStyle.{$ENDIF}fsUnderline];
      end;
    end
    else
       ACanvas.AssignFont(InternalFont);
  end;
{$ifdef HH_PATCH_TEETREE}
  aCanvas.Font.Color:=ColorToRGB(aCanvas.Font.Color);
{$endif}

end;