procedure TMainForm.PageControl1DrawTab(
  Control: TCustomTabControl; TabIndex: Integer; const Rect: TRect;
  Active: Boolean);
const
  Tops: array[Boolean] of Integer = (0, 4);
  Lefts: array[Boolean] of Integer = (4, 8);
var
  NewRect: TRect;
begin
  with Control.Canvas do
  begin
    NewRect := Rect;
    if Active then
    begin
      NewRect.Top := NewRect.Top + 2;
      FillRect(NewRect);
      Brush.Color := clBtnFace;
      Font.Color := clHighlight;
    end
    else
    begin
      NewRect.Top := NewRect.Top - 2;
      FillRect(NewRect);
      Brush.Color := clGray;
      Font.Color := clHighlightText;
    end;
    TextRect(NewRect, Rect.Left + Lefts[Active], Rect.Top + Tops[Active], TPageControl(Control).Pages[TabIndex].Caption);
  end;
end;

TextRect(NewRect, Rect.Left + Lefts[Active], Rect.Top + Tops[Active], '11111111111');