title: RRD Graph - Change line colour by value
body: <p>I have a RRD database with data:</p>
  
  <pre><code>    "DS:pkts_transmitted:GAUGE:120:0:U",
      "DS:pkts_received:GAUGE:120:0:U",
      "DS:pkts_lost:GAUGE:120:0:U",
      "DS:rtt_min:GAUGE:120:0:U",
      "DS:rtt_avg:GAUGE:120:0:U",
      "DS:rtt_max:GAUGE:120:0:U",
  </code></pre>
  
  <p>And I want that the Avg line change colour if I lose any package.</p>
  
  <p>For example, if I lose 5 packets make the line blue, if I lose 10 make it red.</p>
  
  <p><a href="https://i.stack.imgur.com/eKE70.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/eKE70.png" alt="enter image description here"></a></p>
  
  <p>I see people doing it but I read the documentation and I can't find how to do this.</p>