Borders borders = new Borders(
                    new Border(), // index 0 default
                    new Border( // index 1 black border
                        new LeftBorder(new Color() { Auto = true }) { Style = BorderStyleValues.Thin },
                        new RightBorder(new Color() { Auto = true }) { Style = BorderStyleValues.Thin },
                        new TopBorder(new Color() { Auto = true }) { Style = BorderStyleValues.Thin },
                        new BottomBorder(new Color() { Auto = true }) { Style = BorderStyleValues.Thin },
                        new DiagonalBorder())
                );