title: D3 collapsible tree, change colour of knots and avoid line/text overlap
body: <p>So here I am with this d3 tree:</p>
  
  <p><a href="http://plnkr.co/edit/HwcZecZtLor51cyNSGSL?p=preview" rel="nofollow">http://plnkr.co/edit/HwcZecZtLor51cyNSGSL?p=preview</a></p>
  
  <p>As you may see, the tree is a bit complex and some of the leave names may be quite long. My main questions are:</p>
  
  <p>Can we change the colour of specific knots (some blue, some red)
  and is there any way I can make it so that the text of a leave does not overlap with the link with the previous level? This happens especially when the link is a straight line.</p>
  
  <p>My JS skills are lacking to say the least as these are my baby steps into this world and any help would be greatly appreciated.</p>
  
  <p>Thanks!</p>