你可以像一些VCL组件那样做：在TITemsFrame类上公开一个事件OnDrawItem，其中包含可以为每个项修改的所有参数。
范例：

TItemsFrame = class(TFrame)
...
  fExternalDrawEvent : reference to procedure (out OItemColor : TColor);
                       // or procedure (out OItemColor : TColor) of object
  procedure DoExtDraw(out OItemColor : TColor);
...
public
...
  property OnDrawItem : TExternalDrawEvent read : fExternalDrawEvent write fExternalDrawEvent ;
...
end;

TItemsFrame.DoExtDraw(out OItemColor : TColor);
begin
  if assigned(fExternalDrawEvent) then
  begin
    fExternalDrawEvent(OItemColor); 
  end;
end;

procedure TItemsFrame.DrawingItems ;
var 
  lItemColor : TColor;
begin
  ...
  if fExternalDrwaingEnabled then
  begin
    DoExtDraw(lItemColor );
  end;
  ...
  Item[i].color := lItemColor ;
  ...
end;

例如第一个程序：

procedure 
var 
  lExampleFrame : TFullPage;
begin
// Create
  lExampleFrame.OnDrawItem(
    procedure (out OItemColor : TColor) 
    begin
      OItemColor := clred; 
    end
  );  

end;

例如第二个程序：

procedure 
var 
  lExampleFrame : TFullPage;
begin
// Create
  lExampleFrame.OnDrawItem(
    procedure (out OItemColor : TColor) 
    begin
      OItemColor := clBlue; 
    end
  );  

end;