title: Change color of Highlight annotations in PDF with python
body: <p>I want to change the color of existing highlight annotations in a PDF file with python and popplerqt4. I have a PDF document with existing HighlightAnnotations. For a given page, I can retrieve the annotations by using:</p>
  
  <pre><code> In [1]: doc = popplerqt4.Poppler.Document.load('doc.pdf')
   In [2]: annotations = doc.page(0).annotations()
  </code></pre>
  
  <p>which in that case returns two annotations of type Highlight.</p>
  
  <pre><code> In [3]: annotations
   Out[3]: 
   [&lt;popplerqt4.HighlightAnnotation at 0x7f4cbc170948&gt;,
    &lt;popplerqt4.HighlightAnnotation at 0x7f4cbc170558&gt;]
  </code></pre>
  
  <p>Now I can change the author or change the quads of these annotations with respectively the <code>setAuthor()</code> and <code>setHighlightQuads()</code>methods. This works perfectly and it has the expected behavior when the document is  saved (with <code>pdfConverter()</code>).</p>
  
  <p>My question is, given <code>annotations</code> above, what is the proper way to change the color of the highlight ? I've seen in a couple of c++ examples that they use <code>annot-&gt;style().setColor( RED );</code> for instance. How can I access the style property of my annotations with python ? In my example I have only access to the attributes below. Thank you in advance for any hints !</p>
  
  <pre><code>In [4]: annot = annotations[0]
  
  In [4]: annot.
  annot.ACaret               annot.Dashed               annot.NoEffect             annot.creationDate
  annot.AFileAttachment      annot.Delete               annot.None                 annot.flags
  annot.AGeom                annot.DenyDelete           annot.Quad                 annot.highlightQuads
  annot.AHighlight           annot.DenyPrint            annot.Rejected             annot.highlightType
  annot.AInk                 annot.DenyWrite            annot.Reply                annot.modificationDate
  annot.ALine                annot.External             annot.RevScope             annot.setAuthor
  annot.ALink                annot.FixedRotation        annot.RevType              annot.setBoundary
  annot.AMovie               annot.FixedSize            annot.Solid                annot.setContents
  annot.ASound               annot.Flag                 annot.Squiggly             annot.setCreationDate
  annot.AStamp               annot.Group                annot.StrikeOut            annot.setFlags
  annot.AText                annot.Hidden               annot.SubType              annot.setHighlightQuads
  annot.A_BASE               annot.Highlight            annot.ToggleHidingOnMouse  annot.setHighlightType
  annot.Accepted             annot.HighlightType        annot.Underline            annot.setModificationDate
  annot.Beveled              annot.Inset                annot.Unmarked             annot.setUniqueName
  annot.Cancelled            annot.LineEffect           annot.author               annot.store
  annot.Cloudy               annot.LineStyle            annot.boundary             annot.subType
  annot.Completed            annot.Marked               annot.contents             annot.uniqueName
  </code></pre>
  
  <p>I'm using the packages below:</p>
  
  <pre><code>python -V
  Python 3.4.3       
  
  popplerqt4.version()
  (0, 24, 0)
  
  popplerqt4.poppler_version()
  (0, 30, 0)
  </code></pre>