Aspose. Pdf, Text TextFragment set the foreground color, background color is not transparent.
textFragment.TextState.BackgroundColor = Aspose.Pdf.Color.Black;
//Don't work
textFragment.TextState.ForegroundColor…...solid black, it looks like the alpha from the foreground color is...(int p = 1; p < 17; p++) { var alpha = (p - 1) * 16; Color systemColor...