Does anyone have any ideas on how to set the background color on the PdfSignatureAppearance rectangle in iTextSharp? I create the PdfSignatureAppearance object and can set its positioning on the page, but the rectangle only has a transparent background. I'm trying to apply a color (any really).

I've tried creating a new iTextSharp.text.Rectangle then setting the `rect.BackgroundColor = new BaseColor(System.Drawing.Color.Yellow);` That doesn't work. I saw someone else trying to something similar by applying the styles to the layer2 of the signature appearance object. I've tried these with no luck. 

```
PdfTemplate sigAppLayer2 = appearance.GetLayer(2);
sigAppLayer2.SetRGBColorFill(255, 0, 0);
sigAppLayer2.SetGrayFill(2);
sigAppLayer2.BoundingBox.BackgroundColor = new BaseColor(System.Drawing.Color.Yellow);

```

Anytime I try one of the above styling changes to the layer2 the visible signature disappears on the PDF. If I try applying it to layer 0 or layer 1 then nothing happens. I'm assuming then I'm touching the correct layer (2).

Any ideas? The goal is to just get a background on the signature box vs having it be transparent.

See comment below. I tried this as well setting against layer 2 and layer 0. Both result in a red box, but the signature text is missing.

```
PdfTemplate sigAppLayer2 = appearance.GetLayer(2);
Rectangle rect = sigAppLayer2.BoundingBox;
PdfTemplate sigAppLayer0 = appearance.GetLayer(0);
sigAppLayer0.SetRGBColorFill(255, 0, 0);
sigAppLayer0.Rectangle(rect.Left, rect.Bottom, rect.Width, rect.Height);
sigAppLayer0.Fill();

```