type
  TIEColorType = (ieGrayScale, // grayscale
    ieBlackWhite, // black and white
    ieColor, // colored
    ieUnknown);

function GetColorType(AIEBitmap: TIEBitmap): TIEColorType;
begin
  if AIEBitmap.Bitcount = 1 then
    Result := ieBlackWhite
  else if AIEBitmap.IsGrayScale then
    Result := ieGrayScale
  else if AIEBitmap.PaletteUsed > 2 then
    Result := ieColor
  else
    Result := ieUnknown;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  if OpenPictureDialog1.Execute then
  begin
    ImageEnView1.IO.LoadFromFile(OpenPictureDialog1.FileName);
    ImageEnView1.Update;
  end;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  ImageEnView1.Proc.ConvertToGray;
  ImageEnView1.Update;
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
  ImageEnView1.Proc.ConvertToBWOrdered;
  ImageEnView1.IEBitmap.Bitcount := 1;
  ImageEnView1.Update;
end;

procedure TForm1.Button4Click(Sender: TObject);
var
  ieColorType: TIEColorType;
  iColor: string;
begin
  ieColorType := GetColorType(ImageEnView1.IEBitmap);
  case ieColorType of
    ieGrayScale:
      iColor := 'grayscale.';
    ieBlackWhite:
      iColor := 'black and white.';
    ieColor:
      iColor := 'colored.'
  end;
  MessageBox(0, PChar('The bitmap is ' + iColor), 'Color',
    MB_ICONINFORMATION or MB_OK);
end;