type
  TAncestor = class
   ...
  protected
    property Size: Integer read FSize;
    property Text: string read GetText write SetText;
    property Color: TColor read FColor write SetColor stored False;
    ...
  end;
type
  TDerived = class(TAncestor)
   ...
  protected
    property Size write SetSize;
  published

    property Text;
    property Color stored True default clBlue;
    ...
  end;