title: graphviz: direction of edges in terms of color
body: <p>Hi<br>
  Can I get graphviz to color the edges in a way that identifies the direction? For example, the  part of the edge near its source node might be blue and then it gradually shades away to red as it nears the target node. Or are there any other graphing tools (like graphviz) that can do this?</p>
  
  <p>Any help in this regard would be much appreciated. </p>