procedure TForm1.Button1Click(Sender: TObject); 
begin 
  with WebBrowser1 do 
  begin 
    OleObject.document.body.Style.scrollbarArrowColor := '#0099FF'; 
    OleObject.document.body.Style.scrollbar3DLIGHTCOLOR := '#FFFFFF'; 
    OleObject.document.body.Style.scrollbarDarkShadowColor := '#0099FF'; 
    OleObject.document.body.Style.scrollbarFaceColor := '#99CCFF'; 
    OleObject.document.body.Style.scrollbarHighlightColor := '#0099FF'; 
    OleObject.Document.body.Style.scrollbarShadowColor := '#0099FF'; 
    OleObject.Document.body.Style.scrollbarTrackColor := '#FFFFFF'; 
  end; 
end;