title: iText 7 - How to fill a canvas rectangle with a transparent color
body: <p>In iText 7.1.9 I am taking a pdf created programmatically (not via iText) and need to apply a transparent rectangle along the left side and bottom to ensure the no content exists within a predefined clear zone (for print).</p>
  
  <p>The below code places the yellow rectangles correctly but the desired result is the for the yellow fill to be semi-transparent or not 100% opaque so that visual inspection will show the content that that intersects with the rectangle instead of the rectangle clipping the content.</p>
  
  <pre><code>var page = pdf.GetPage(1); 
  PdfCanvas canvas = new PdfCanvas(page);
  canvas.SaveState();                
  canvas.SetFillColor(iText.Kernel.Colors.ColorConstants.YELLOW);
  
  var pageHeight = page.GetPageSize().GetHeight();
  var pageWidth = page.GetPageSize().GetWidth();
  // left side
  canvas.Rectangle(0, 0, 15, pageHeight);
  // bottom
  canvas.Rectangle(0, 0, pageWidth, 15);
  canvas.Fill();                
  canvas.RestoreState();
  </code></pre>
  
  <p>I attempted to use a TransparentColor but canvas.SetFillColor won't accept a TransparentColor, are there any other options?</p>