title: How to make a gradual color bar for representation of risk analysis results in R?
body: <p>I want to plot results of risk analysis that categorized by 4 levels (No risk, low, moderate and high risk) on gradual color bar (green-yellow-red).
  I thought about something like this (but I'm open for nicer suggestions.)<br>
  <a href="https://i.stack.imgur.com/heYxs.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/heYxs.jpg" alt="enter image description here"></a></p>
  
  <p>The input is something like this</p>
  
  <pre><code>results &lt;- data.frame(matrix(nrow = 5,ncol = 0))
  results$day &lt;- c(1:5)
  results$assessment &lt;-c("Low","Moderate","High","Low","Moderate")
  </code></pre>