-----------------------------------------------------------------------
            "Delphi X-Files" <www.DelphiXFiles.narod.ru>"
                        "Перевод RGB в GRAY"
-----------------------------------------------------------------------
  
function RgbToGray(RGBColor : TColor) : TColor; 
var 
  Gray : byte; 
begin 
  Gray := Round((0.30 * GetRValue(RGBColor)) + 
                (0.59 * GetGValue(RGBColor)) + 
                (0.11 * GetBValue(RGBColor ))); 
  Result := RGB(Gray, Gray, Gray); 
end; 

procedure TForm1.FormCreate(Sender: TObject); 
begin 
  Shape1.Brush.Color := RGB(255, 64, 64); 
  Shape2.Brush.Color := RgbToGray(Shape1.Brush.Color); 
end;