var
  FIcon: TIcon;
  FStream: TStream;
...
  FStream:=TMemoryStream.Create;
  Try
    TBlobField(FieldByName('icon')).SaveToStream(FStream);
    FStream.Position:=0;
    FIcon:=TIcon.Create;
    Try
      FIcon.LoadFromStream(FStream);
      FImageList.Height:=32;
      FImageList.Width:=32;
      FImageList.ColorDepth:=cd32Bit;
      FImageList.AddIcon(FIcon);
    Finally
      FIcon.Free;
    end;
  Finally
    FStream.Free;
  end;
...

var
  NewBitmap: TBitmap;
...
begin
  NewBitmap := TBitmap.Create;
  try
    NewBitmap.PixelFormat := pf32bit;
    NewBitmap.Height := FIcon.Height;
    NewBitmap.Width := FIcon.Width;
    NewBitmap.Canvas.Brush.Color := clWhite;
    NewBitmap.Canvas.FillRect(NewBitmap.Canvas.ClipRect);
    NewBitmap.Canvas.Draw(0, 0, FIcon);
    FImageList.AddMasked(NewBitmap, clWhite);
  finally
    NewBitmap.Free;
  end;
...