procedure TForm1.Button1Click(Sender: TObject);
var
  x,y,z, R, G, B, v: integer;
  ielab: TCielab;
  iergb: hyiedefs.TRGB;
begin
     memo3.Clear;

     for R := 0 to 15 do
      for G := 0 to 15 do
        for B := 0 to 15 do
        begin
          iergb.r := r;
          iergb.g := g;
          iergb.b := b;
          ielab := IERGB2CIELAB(iergb);
          rgbcolor := IeCielab2rgb(ielab);
          if (iergb.r <> rgbcolor.r) or
             (iergb.g <> rgbcolor.g) or
             (iergb.b <> rgbcolor.b) then
         begin
            memo3.Lines.Add('RGB :'+ inttostr(r)+','+inttostr(g)+','+
                                     inttostr(b)+' <> '+
                                     inttostr(rgbcolor.r)+','+
                                     inttostr(rgbcolor.g)+','+
                                     inttostr(rgbcolor.b));
         end;

 if (Y > 0.008856) then
  begin
    fY := IEPower2(Y, 1.0/3.0);
    // ################## +0.2 
    L := 116.0*fY - 16.0 +0.2;
  end
  else
  begin
    fY := 7.787*Y + 16.0/116.0;
    // ############# + 0.2
    L := 903.3*Y+ 0.2;
  end;